Toyed around with "meh" geared toons and for what I've seen Warriors ate well, al specs had rather significant buffs (Prot's Execute is nasty), Shamans are in the same bucket though only Enhancement recieved buffs that were as sizeable. Ele and Resto still got nice buffs though nothing too significant.
Hunters are overall better, I think BM is a bit worse but MM is so much better since we can still have a pet, even higher damage and solid AoE now.
Idk how much changed on Warlocks but Drain Life seems to have been buffed by a large amount (feels like it's been buffed by maybe 400%) so it's basically a full heal over maybe 2-3 seconds or even maybe one on a crit which is crazy work.
All specs of Priest Paladin, DK, DH, Rogues and Monk are all overall better, mostly positives here. Not many huge buffs (a big damage buff for tank specs it seems) but still nice ones.
Mage hasn't seen much change (at least nothing major for 20s).
Druid feels about as strong for most specs, Resto did get nuked damage-wise but we got Moonkin back and extra healing so not all bad.
Idk about Evokers.
I feel like overall Warriors (all specs), Warlocks(all specs), (especially Enhance) and Hunters (especially MM) are the ones that benefitted the most from 11.1 (Priest Paladin, DK, DH, Rogues and Monk really aren't far, they ate well too) but it kinda feels like everyone got something, no spec got purely negative changes (again, idk about Evokers so maybe them).