A recent post here discussed baseboard installation. I was interested since I am currently replacing ours in the FR (and eventually other rooms).
The original base was painted with the shoe being stained the color of the oak floors. I was going to repeat this with the new basebord.
However, upon investigation (my 3 or 4 trim books), I noticed that most of the upgraded baseboard pictured had painted shoe on stained floors.
As I though more about it, I came to the conclusion that builders probably have the floor installers put on stained shoe so that the trim guys don't have to come back to install the painted stuff over the freshly installed floors. In other words, it's one of those details that is just convenient/cheaper (like much of the crap in new construction) since the wood floors are the last thing installed (around here anyway).
I know it's not THAT critical and that we will eventually do what we like - probably going with painted shoe this time around.
Just thinking out loud...
Lou