Er, half the framerate. I don't think people fully understand the nature of a BLB - they're meant to be relatively basic geometric shapes to keep framerate high and the game playable. As soon as people are converting high quality models into bricks, things start to get choppy and in that case - no, more bricks is not better.
I believe Trader meant "quality", as in, efficient, looks good, and doesn't have any errors. I mean, I sure as hell wouldn't release a .blb-making program, there has to be some quality control.