I don't know if there's a huge server/db impact, but especially in Indie Design I think we definitely need more than 21 threads per page. Just to get more exposure for peoples' projects (I personally keep losing track of items once the drop off the second page, and never go past the second page really), I'm thinking if it's possible to change the number of threads/page for a specific forum, then maybe 40 or so would be good for Indie Design. If not, setting a global of 30 would help all around, I'd wager.
Just a thought.
-Andy