It's very good. Karazhan is the first adventure that didn't require abusing some weird gimmick, thus it's much easier. Previous adventures were a pain, Kara can be done with various methods.
This is true, some of the earlier Adventure bosses even relied on plain luck to beat them which doesn't mean they were hard. It means lazy design 'making things hard for the sake of being hard' instead of actually giving a fair challenge to people. I actually prefer making three attempts at a real puzzle than to retry the same match 8 times before I got the exact mulligan to beat it.
Blizz really needs to find a mid point between far too easy and just plain unfair.