I've put 4500 miles on two pairs of Pegasus 30s and they're finally starting to fall apart. I tried some 33s and 34s and they both feel like like they have cushions in the forefoot, which restricts my stride a bit and I hate it.
I also tried the latest DS Trainers for something basic and lightweight, but after a couple miles got a pretty bad blister on the side of my heel (from the shape/size of the heel cup I guess).
I'm looking for something simple without too much cushioning and without a huge drop from heel to forefoot.