I'm liking this new update just because the netcode doesn't feel near as shitty. I think it feels pretty good now and I'm not having rockets/rails/nailgun do no damage when I see the shots hitting enemy gamers. Also the new maps are very aesthetically pleasing. Doom Guy is also pretty fun. He runs at like a million miles an hour with his ability.
I don't think the new duel mode is near as good as classic duel but it's fun to play with friends who haven't played much Quake before. I'm a pretty shit duel player but if I play newer players to Quake in Quake Live I can roll them pretty hard without even chasing frags because they just put themselves in bad spots without realizing it. With the new mode sometimes I'll lose a few champions or a round. They should still have a classic duel mode though.