Just finished building my somewhat modest master bath addtion (I did all the plumbing myself). My experience deals with a stand up shower in this particular instance. After some resarch, I decided that I did not need to spend north of $2k on Kohler thermo valve, and I did not need 15+ GPM with 3/4" inlets. By the time I added the body sprays and a couple of shower heads i was in for over $3k which was way over budget. I ended up doing a Moen Vertical Spa. IIRC, I think it was about $1,300 with two shower heads, 4 body sprays, a handheld shower, 5 position diverter valve, and the thermo mixing valve. I just fired it up last week and am very happy with the whole set up. Moen does a nice job, they have some great info on their vertical spa and thermo valves on the moen.com website. It took me a full day to pipe, but I used long radius elbows and took my time to ensure good flow. Having both the pressure balanced and a thermo valve, I prefer the thermo valve and being able to adjust the flow volume. Plus I think it looks better. I ordered it online from faucet.com, no tax + free shipping....plus they price match. If you google the part number and you find a lower price and email it to the price match department and they re-quote the product. Customer service was superb and ended up ordering my sinks, faucets, med. cabinets, and towel/TP holders from them. Again, with no tax and free shipping the net result (to me) was a great deal. I go out of my way to keep from purchasing at the big box - but that might be my personal grudge, but they dont have anything "good" in shower valves in stock any ways, so why bother ordering it from them? Hope that helps.

You must be a real blast at parties with how negative you always are. Can you please just not comment on my posts? on demand hot water heater does 5gal/min, shower heads are 1.8-2.0, body misters are .08gpm @45psi and i'd have 6. my pressure tank keeps my pipes at 45+psi no problem. My plumber said they dont care about dual valves where i live and since i'm doing class K, I only have a final inspection which is a walk through to make sure the house isn't going to tip over. Thanks for your very insightful, and once again wrong contribution to the conversation.

The trim kit is useless without the right valve in the wall. It’s not interchangeable either. Koehler fits Kohlet valves and Delta fits Delta valves. What the right valve is, depends on your needs. A simple tub shower is usually under $500 for everything in chrome, in a basic style. Start adding fixtures that need multiple output ports, or going into specialty finishes like brushed brass, and the valves and trim both change. And you can have 2K in shower plumbing in a heartbeat. If you are getting large numbers, then it’s your requirements to do what you want that are driving the numbers. You contro the pricing by cutting back on the features and finishes.

I'd rather go vertical than across three walls and through two framed corners. If this is soldered copper and a remodel, soldering unions in a 3-stud framed corner can be a pain. It can be easier if the framing is open in new construction, or if the walls are lightweight construction, a partition end stud and drywall clips. If this is hard pipe, my overall goal would be to minimize the number of turns the plumbing has to make from the supply valve to the shower head. Secondary would be the shortest run of tubing. My own shower, I went across the ceiling. That gave me the fewest turns and shortest route.