I think the only problem you might encounter is that if you chip the ceramic you will see whatever the color that's underneath(most white), porcelain has color all the way thru the whole tile.

that's not exactly true. Not all porcelain color goes all the way through. The link below might help...

Here is a link that might be useful: Tileusa

Porcelain is hands down the better tile. But for residential use, conventional ceramic is MORE than good enough. The thing you want to watch for is the PEI rating (Porcelain Enamel Institute), on the glaze. Ratings go from 1-5, one being something that'll scratch if you look at it, and 5 being a tile you could drive a mack truck over.... with spiked tires!

Seriously, a PEI rating of 3 or more should be more than sufficient for anything your floor might face.

incidentally, glazed porcelain (and ONLY GLAZED porcelain) also uses this rating system.

Ceramic usually has a red/brown body, porcelain is either white, tinted to match the glaze [though considerably lighter in tone], or color body/color through.

Porcelain is stronger, but for 90% of residential use, ceramic is plenty strong-- consider that glazed tile is the last surviving remnant of many ancient civilizations, and that you can buy ceramics from the time of the Roman empire on Ebay for a few bucks.

A couple cautions: if your kids are waaay out of control, the porcelain could be better in that it resists cracks. But if it's properly set and supported, they'ed haved to drop a shot put or the like to crack regular ceramic.

I like porcelain for kitchens in case someone drops a very heavy skillet or similar, though.

And in the bath, the color body porcelains tend to offer better traction. Look for the CoF numbers on the tile you like [if you can't find it, ask the salesman to track it down]. CoF is Coficient of Friction, and measures grippiness. Higher is better. Try sliding your foot accross a sample, both wet and dry, and never use a tile in a wet location that is at all slippery-- the EMTs won't care about your lovely tile while sliding your naked tush on a gurney because you've taken a tumble.

So one other tile I'm looling at is Daltile Vibe, colorbody porcelain. The measure for slip resistance(C1028) is as follows:

lightly polished - wet is greater than or equal to .50
dry is greater than or equal to .60
Unpolished - wet is greater than or equal to .60
dry is greater than or equal to .70

are these #'s OK? Thanks

Those are good numbers. The best test is to get a sample of the tile, put it in the shower, turn the shower on, get in the shower and step on the tile. If it doesn't feel slippery underfoot, you've got your tile.

Yeah-- if you go flyin, choose another tile! :-)

If I do decide to go with the Daltile(slip resistance #'s above) does the slight differential in slip resistance make a difference if I go with unpolished or lightly polished?

Not really.

Malhgold, I am so grateful to find that there are indeed a small scattering of other people who do go to this degree of research. They're all on this (and the kitchen) forum.

And, no, none of us are "mere mortals."

;-)