If 8.2 is as cool as it looks, and 8.3 delivers, bfa might be quite better than legion in the end. With heroic warfronts, island fixes, additions and currencies, a whole new endgame zone in 8.2 (and we could get another one in 8.3)... It's only missing a mage tower challenge, and I'm pretty sure we'll have one.
Also de megadungeon will be actually 100% new, unlike Kharazan.