I too am building a pool - they only offer Diamond Brite or Pebble Tech. Since it was $6000 more for the Pebble Tech - we stayed with the "standard" Diamond Brite.

My father-in-law's pools (3 in the last 4 years) have all been Diamond Brite plaster pools - yes they can get really rough IF you don't take care of them and the plaster starts etching (really low PH). If they are taken care of they are fine. My kids have been swimming in pools for years that have Diamond Brite and they have never complained about it being rough.

If it really concerns you - check out Pebble Sheen - it is really expensive but it is supposed to be like a granite finish more than a pebble finish - very smooth.