Unfortunately, the bed thickness is dictated for me. You may remember my attempts to find a suitably thin lintel to cover the double appliance gap for the granite. Due to the low windows sills (early Edwardians didn't have fitted kitchens...) I need every single mm. Even a 5mm bed would actually prevent me getting the appliances in, it is so tight.
As it happens, I think I probably have been lucky with the thicknesses. There is one really thin tile in there and around 3 or 4 slightly thicker ones, but the rest all look pretty much identical to a casual glance. Certainly the variation in thickness wasn't as great as I had been led to expect.
I would think there was some variation. This is probably an advantage, as I can blame the tiles! However, I've used this technique before with ceramic tiling. To see the lines, you just scrape a bit of adhesive away to check and then replace it.
Yes, I've gone for grey. I suspect the grout lines will close to disappear. The bamboo I've got is less brown and more grey than that I saw in the showroom, although there are plenty of brown and rust streaks that come up nicely with the colour enhancer.
Christian.