I'll let you know in a couple of weeks. I'm going through exactly the same thing right now, except that the shower was done last november (in a summer home) and used for the first time a few weeks ago, memorial day weekend. There's no rhyme or reason as to how it's appearing in the grout. A little spot here, another one there-- and before the shower was used, the grout was all consistant. I know the mud was the right consistancy, and there's gravel around the weepholes so they're not plugged. The membrane is presloped, so the pan is not holding water, and as you said, even though it looks wet, I can sit there and go back and forth over it with a paper towel, and it (the paper towel) stays dry as a bone. I told the people to let it go another few weeks-- that I'm aware of it, and I would certainly stand behind my work-- and lets see what happens. I have a feeling it may be cosmetic, but we'll see. Remind me in about 3 weeks-- about the middle of july, and I'll tell you what happened. If it turns out that it's just cosmetic, I AM going to use a colorant over the grout.

Here's several sources of irregularities in a tile installation: Unless the tile installer shimmed out the backing to compensate for any wavy studs, you will have a wavy backing, and the tiles will follow the waves ... occasionally one will hit the crest of a wave just right and you have a corner like you see. 2 - With a square-edged tile all the tile installer has to do is wipe ALL the grout off the face of the tiles and it's all even. With a rounded edge the visible grout width will vary depending on how much grout is wiped away from the rounded edge to reveal the joint. That's part of the "charming hand-made" look. Had they known that you wanted machine-like precision in the grout lines they may have been able to warn you that the rounded edges of that tile are not conducive to precise grout joint appearance unless you want to pay for someone to use calipers and Q-tips on all the joints. 3 - Tile size variation depending on where they were in the kiln. It's tiny, but it adds up over the course of several rows of tile. 4 - Those spacers are not "machined" they are cast or pressed into the clay before it's fired, and subject to shrinking. They are a help to the tile setter, not any guarantee of absolute precision. ---------------- As for the spacers, unless your walls were perfectly squared and ceiling perfectly level, some of the joints probably needed to be widened a scooch so the tiles would line up properly with the tiles on the other wall. the easy way to do this is to slip a spacer into the joint and twist it. My tile installer (and contractor) had to compensate for a 1 inch difference between one side of the alcove's rear wall and the other. He did it by starting about three rows up from the rim of the tub and widening the grout gaps a tiny bit on the high side, tapering back to normal on the low side. It looks great, but it took him the better part of three days to do all the measuring, marking, and scooching, then letting each couple of rows set up so he wouldn't mess it up with the next rows.

I am not an expert, but I agree a bullnose would be nice. Google bullnose tile to see what that looks like if you are not familiar. I know on some kinds of tiles (maybe just natural marbles, travertine, etc, though) they can use a grinder to smooth the profile to be rounded, not sharp. Don't know if they can do that with your kind of tile, though. I am in agreement with your PB that the mitered 45 degree wouldn't be ideal, that would make a sharp edge (think about babyproofing a fireplace hearth or something, you gotta put that rubber rounded piece on it to make it safer.)

You don't have to worry about the water "leaking through" since grout and tile are not waterproof anyways -- the waterproofing magic actually happens behind it, which is why everyone on bathroom forums harps on "what waterproofing was used". The grout just serves the purpose of binding the tile surface together for sturdiness and for easier cleaning. You can make your joints whatever size you'd like; for what it's worth, I used the Daltile subways with lugs about 13 years ago and they have held up just fine; I liked the aesthetics of the thinner joint. You will probably want the spacers on hand anyways, there are always little placement situations where the spacers come in handy even if you're largely depending on the lugs. ETA: oh, I see you're also asking about the Daltile variations in quality that might lead to the lugs being uneven themselves. It's a cheaper tile, so we found that there will be the occasional wonky one, but precisely because they're so cheap, you can sort those out pretty easily without losing a lot of cash. I wouldn't be too concerned about this.