lazypup: "I also consider how many of each brand I installed in 35 years and the percentage of customer call backs for each brand" Fair enough; but for the first half of those 35 years, you were installing and removing 5 gallon per flush and 3.5 gallon per flush toilets, and no toilet currently selling in the United States is based on those outdated designs. (You also were not installing Totos back then, because Toto toilets were not yet being marketed here.) Your conclusions also appear to diverge from the experience of Terry Love, who presides over the Internet's largest toilet forum and whose company has installed thousands of toilets. Here is a link that might be useful: A discussion of just this issue on 2011 February 22

jsaklas: "I have the AS Champion and it has NEVER clogged, my Kohlers have always clogged. I never owned a TOTO, but the TOTO Drake has a 20% smaller trapway (2 and 1/8" while the AS has a 2 and 3/8" which is an area 19+% smaller) and a 3" flush valve while the AS has a 4" flush valve, so I think it would be impossible for the TOTO to flush as well as the AS." Your personal experience with a real-world product is a valid testimonial; your rationalization for why is not based on good science. The diameter of the "solids" to be flushed is pretty much limited by human physiognomy. Every -- pardon me for using the proper word -- turd has a diameter that is limited by the orifice through which it passes. You will not find many -- if any -- turds that exceed 2-1/8" in diameter. The length of a turd, however, is less constrained than is its diameter. After passing through the trapway, the turd must make its way into a sewage line. And that is where many toilets made in China (whisper: "American Standard") fall short. You can have a FOUR inch trapway, but if the trapway ends in a 90 degree turn with a tight radius, you will get clogs from time to time. One of the limitations of the MaP test, revered by many, and 99 percent based on an engineering model developed by Toto, is that the MaP test ends at the exit from the trapway. But if a long turd has to make a sharp 90 degree turn from the exit from the trapway, the toilet will clog, no matter how capacious the trapway diameter is.

OK pricklypearcactus, you're making me do alot of research now.... Here's the 3" flapper, model# THU175S, used on Toto "G-Max" 1.6gpf toilets, like the original, now-discontinued Drake: That flapper, from what I've been told, can be replaced by model# THU140S, which was used on their "Power Gravity" 1.6gpf toilets that were their midrange models - G-Max was their high-end. Note the lack of a hole on the side, which keeps it from falling until the water level is lower, thus sending more water to the bowl: But both of those 1.6gpf designs have been discontinued in favor of two 1.28gpf flush systems: E-Max (on most of the "Eco" models) and Double Cyclone (on most of the "II" models). Now here's where things get complicated - all of these seem to use a whole new range of flappers - a quick search turned up at least three new ones - THU253S, THU277S, and THU299S. Amongst the changes, most (all?) of these have added a float that sits above the flapper. I don't know if the float can be adjusted or removed - haven't seen one in person yet. There's a picture of the flapper from the Eco Drake, which I think uses the 277, on Terry's site: (here). To get an idea of the difference, look at the parts diagrams for the old 1.6 Drake and the new 1.28 Eco Drake. Now see the difference in part #6, the flapper? It does seem, as Terry noted, that the rest of the tank (and the bowl for that matter) haven't changed - compare the other part numbers. Maybe all you need to do to convert an Eco Drake into an old-style G-Max Drake is remove the float, or at least swap to the old flapper, although Terry says on his thread that the flush valve is different too. There was a 1.6gpf Double Cyclone in the lineup until recently (on the Neorest, Soiree, and Guinevere) - I can't find what flapper they used. This is way more than I ever wanted to know about toilet flappers....

I guess my response is too late for the OP's information. However, I have replaced toilets in three houses. The first house had two BR's and the next two had three bathrooms. First house was our entry level house in the Los Angeles market; we installed two boring Kohlers that performed well and quietly and I never needed a plumber for anything. Our next move up house was a huge jump up in cost, it was almost double square footage but the premium in cost was mostly because it had an amazing ocean view and marina view and this even from the shower in the master bath. In this house we upgraded with Kohler's San Raphael in the master and guest bath and in the powder room, we splurged on the St. Martin (or San Martine?) an incredibly beautiful toilet with what we thought was a pretty high price tag of over $800, which was a lot for that time period (the early 90s) though not so much in these days of the $3000 "hatbox" toilet from Kohler. None of these toilets ever caused a problem, though our plumber who was the BEST, (JEFF of family-owned and run Argyll Plumbing, if you're reading this out there in Torrance CA. it is you to whom I refer as the BEST) warned us that we possibly could have problems with the high-end San Martine but these never developed, at least not while we still owned the home. Because of a precipitous move downward in the income and wealth index by a lot (thanks to very serious mistakes by physicians at the Jacksonville Fl. Mayo Clinic, mistakes that could and should have been caught and avoided, mistakes that served to end my husband's corporate and international business development career with its comfortable income and more important, true meaning in his life, while at the same time our savings got used up and our retirement funds were almost breathlessly depleted while we looked on, heads spinning, and as we are now, the proverbial unhappy campers, saddled with credit card debt run up in a few years time but that will take years if ever to pay off, and forced to be "re-educated" and to deal with new goals not of our making: like living on a fixed income that has little extra for not much of anything and maintaining a home that we'd rather not, since our goal at the time this all began had been to sell the house and return to the West Coast, our real home, but then this "merde" came our way and by God, did it ever hit the fan!) the Kohlers in our three bathrooms in our current home are more modest models, either the Kohler Highline or the pretty little Kohler Santa Rosa. These toilets got replaced a second time though because of the newly introduced comfort height toilet, this a great feature that hadn't been available in 1999 when we moved into the one-year-old home and immediately upgraded the cheapy contractor's grade toilets, and a feature that we would only come to fully appreciate later on (my husband has had both of his hips surgically replaced,plus one knee, so far) and now wouldn't give up for any reason. We are getting around to replacing the master bath's standard-height Santa Rosa and I've come to this dependable forum for help with our decision. Because decisions like this now take on amazing significance. So rather than replace a Santa Rosa with another Santa Rosa, even as pretty as they are, we are seriously considering the Kohler Persuade Curv. I love the look, its slender beauty and the ease of cleaning the look suggests. (I'm not getting any younger). But I hesitated and have for a while. It doesn't seem possible that Kohler could offer that great look (a smooth bowl that jumped forward into the 21st century, leaving behind the tired look that mimicked the pipes, the interior function) and do it at a price point that actually was possibly attainable by the majority of the toilet-needing masses, this from the company that shocked the world (well, I was shocked!) with the $3000 "hatbox" toilet. After many years of nothing but success with Kohler toilets now when we don't have the resources to reverse a bad decision, the wrong choice, after all I've read about the Persuade, I am stuck. Is going with the Kohler Persuade because of the beauty of the look, (and because I internet shopped and found a very very good price) while I bury my head in the sand as to any problems lurking down the road, problems I learned about also on the internet as I researched WHICH KOHLER TO BUY, is all this by definition telling me I'm in a new world here and to tread carefully with my few precious dollars?