After each major project I want to write a Lessons Learned post about the mistakes (and a few successes) made along the way, and how we dealt with them. You can take a look at my past half-assed attempts by clicking on the posts tagged lessons leared.
Also, deciding to tile the front of the tub and the niches with slate meant we were two floor tiles short. Luckly Home Depot was able to get the tile for us quickly. Moral of the story, make sure you have enough trim and buy plenty of extra tile (or plan better) and be wary of buying a specialty color/type of tile, as purchasing additional tile may be tricky. In the end, all is well as we spent about $600 on all the tile in the room, which is pretty cheap considering how it all came out.
We also did the quote as labor only, as we had already purchased the materials. If you are using high end materials, realize it might be better to pick out yourself and price separately as it is just too hard for a contractor to bid the job.
The color temperature is easy to fix. I did some research and found our bulb is a 3500K bulb, which is a cool-bluish white. Not appealing in the bathroom, as it casts a ghostly bluish pallor to the sking. We want a 2700K bulb, which is a tungsten balanced bulb that puts off the warm and cozy orangish glow we are used to.
The issue of being dim when it starts up is more complicated. Looking up the light I found it's spec sheet. After skimming through a lot of gobbly'd'gook I finally found evidence of what I was looking for on page 6. This page shows a graph of lumen output as a function of time. At start up, this bulb only puts out 20% power, and take 2-3 minutes to come up to full power! If you are just going in to use the bathroom quickly, this is far too long to wait. Since the bulb is 4 pin, it requires an electric ballast be installed in the light for it to work. Now I don't know if the poor light output at start-up us due to the light, or to the ballast. With lights running at around $10 a pop plus shipping I am not excited about ordering new bulbs only to find out they take just as long to get bright. I wish I would have just gone with a normal incandescent fixture and fit it with a CFL. :-(
I read up on prepping subfloors in Tile Your World, and even looked at John Bridge's Tile Forum. I suggest checking both resources before tiling a floor. He recommends a floor that has deflections less than 1/320 for ceramic tile and 1/720 for natural stone. My floor is slate, so I knew it had to be stiff.
After demo'ing the room I stepped in spots and could feel the floor deflecting below my feet. While the Deflect-O-Later said I was ok for tile, the deflections I felt told me otherwise. I had just planned to add a layer of subfloor over top of my floor, but after feeling this we decided to rip out the old subfloor and sister the joists and add cross bracing to stiffen up the area. Also, we laid new subfloor and 1/2" hardiebacker cement board on top. I am very glad we took this step, because if not it could have been a very expensive thing to fix down the road, as the entire room would have to be ripped up.
If I think of more things in the future, I'll just add to this post.