No, wait. I'm not talking about percpetion of refresh speed. What I'm talking about is a CPU/Graphics engine issue. The way you can't run a game as fast when your display is set to 1280x1024 24bit as opposed to 800x600 8bit. Or the way a computer display can't set it's refresh rate (mhz) as high when it's at a higher resolution (with CRT's at least, LCD's are a different animal). There's so much more graphical information to be processed at the higher resolution that it performs the refresh slower.
I was thinking that since the Sony is 800x600/4 colors vs. 1024x768/16 colors, it's system has less work to do, and can therefore render pages quicker.
But now that I've seen that the BBeB format pre-renders, I'll just assume that's the reason for the speed increase.
And I'll continue watching, waiting, and drooling.
Edit:
Also wanted to say thanks NatCh for the correct info on the sony reader and pdf/txt/html docs. I was under the misconception that they would have to be run through a converter to be displayed.