It's bad only because it's alot of added expense for very little value. Yes, the cork will add insulation. However, it's overkill, as is (I believe), epoxy grout in residential installations. The worst is that both products are very expensive, especially the epoxy, which will cost about 6-8 times the amount as conventional grout. (3 units of epoxy, covering about 50 feet of 12x12 w/1/4" joints a piece will cost about 35.00, while a bag of grout, covering 125 feet of the same tile and grout joints, will cost about 15.00) dlm99-- you could cut the bullnose into 2" pieces, use them on the inside of the niche to cap the wall's tile which would be cut to come flush to the edge of the niche's return.

There's actually a dealer who's been pushing his wares here (linked below), and he's got a pretty good selection of preformed niches. That said, if you have an installer who's not afraid to make his own, he can lay out th framing so as to make the niche fall cull all the way around, and it'd look much better that way. Either way is acceptable, though, and the preformed would be much less expensive. Here is a link that might be useful: Tile Depot

My feeling about shelves (or anything) protruding or projecting from tub or shower walls, is to avoid them. I am a total klutz, and have been known to whack my elbow(s) on the recessed niche/shelf in my own bathroom (while reaching to take something from the niche, or, while putting something back. Having something projecting outward is just asking for an "ouch!" for a klutz like me. I've seen some beautiful, sill-like shelves in niches, but as flush as possible would still be my preference.

Reviving this thread as I have purchased the Pottery Barn 30" navy vanity & brass round mirror to go above it. I'm still struggling with whether to demo the niches and hang a piece of art in each's place or to keep the niches and put shelves in. My contractor said the price would be equal for both options. It seems if I demo the niches and hang art in it's place then there really isn't a purpose as to why the walls in the room are at an angle. But, if I decide to keep the niches and put in shelves, then I'm left with what the heck to put on the shelves. Then I'm tasked with finding decorative items to fill the shelves with (I've already looked several times at HomeGoods, Target). Just want to get a vote on what everyone thinks I should do. I'm keeping the floorplan as is. Pics of the vanity, mirror, and proposed artwork (for the demo the niche option) are :