It's not actually that DW is somehow perfect that makes me like it: it's that it started from the assumption that LJ is A Good Thing, and they are being fairly cautious about making little improvements while still keeping it nearly identical in most respects.

Yes, this. I have NO idea where all the sneering "Oh, everybody thinks DW is perfect and full of rainbows and kittens" BS is coming from, because nobody I know thinks anything like that... and it rather annoys me to be accused of it, merely because I'm on both sites.