I take back what I said at the patch release. It looked interesting but actually it's a mess again.
NG is out of control with the boost on the opponent side. I am easily doing 100 point swing with 1 card. Geralt Yrden is a must from now on in each deck.
Wild Hunt is almost broken too.
There are certainly several much more powerful card and combos out there than I had anticipated, but I at least need more time with them and learning how to counter them before declaring them out of control.
Except for broken combinations with Tir Na Lia, Wild Hunt seems very lame -- insufficient on both points and control.
New SY cards are so buggy you can't really tell whether they are good.
I'm not impressed with the new ST cards, but ST is not my favored faction -- I may be using them badly.
NG opponent boost is definitely wild, but I'm not sure a well balanced deck played well can't counter it. I have been consistently beating NG without Yrden -- even not always playing well. But I don't have many games, many opponents badly misplayed, and I have primarily played either my own NG (which has more control than my typical opponent's) deck or an NR deck with lots of control and units which don't have to go tall on their own. Beauclair could a problem on the same order as Tir Na Lia -- certainly without it, the NG opponent boosts are far less threatening.
SK warriors seem very strong when I encounter them, but I haven't really played them yet.
As was pointed out by DRK3, NR's new cards have been badly underestimated by most players -- and they open options in a lot of different directions.
If nothing else, the new expansion gives a lot to explore, has removed several very binary play options (although it may have created new ones), and is allowing more card interactions (which means more strategy) than many of the recent, previous expansions.