Loading time isn't an issue -- it takes a LOT of text to make a difference there. It's more an issue of convenience in seeing things when paging up and down on Boing Boing... I regularly don't follow links the first time I see something here; come back later and find it to do so; check discussions for new entries (yes, I know I could subscribe); and otherwise revisit recent entries in fairly random order. A single entry multiple screens long makes that more difficult. That's why I have the preference I stated.
I dislike saying anything complaintish about volunteer projects whose results I enjoy. So let me
repeat myself: Boing Boing rocks and I'm grateful for your and Cory's and David's work in making this one of the best places on the web. Thank you.
And that's a story I'll stick to regardless of whether you're persuaded to use 'more' links for very long entries.