Slothrop
Tight but Polite
I'm loving IJ, chipping away at it in what seem like infinitesimal (no pun intended) chunks of a few pages at a time every few days. It's by no means a page-turner but I don't find it a huge effort to read, either. I don't think it's anything like as textually dense as it could be, put it that way, given the level of technical, psychological, political (etc....) detail DFW goes into. He's even got me to care about the tennis stuff.
I found it got pretty page-turny about half way through, when the plot actually got going...