It was interesting reading contrary opinion, backed up by Craven and Wamma's like, so would be great to hear contrary opinion.
I think that the aspect of First Snow that are problematic are aspects of the game that were already problematic - the swinginess of first turns, particularly with regards to the reliance on big characters. So maybe I'm somewhat numbed to the downsides? Like, Greyjoy can make First Snow work amazingly if you get out Asha and Theon, Lanni can put it to great use with Jaime and can utilise Tywin to push big characters out, etc., but those things were true anyway, so to me it feels just like one more tool in that regard. That's the bad side in the current meta, and it's not making the game worse in that regard for me than it already was.
Meanwhile, it opens up a lot of new ground. Once you get past the first round or two, it changes from a swingy hand-attrition plot to, despite what it looks like, an anti-big character plot. Sure, if you only run characters of cost 3 or lower, you'll be in serious...proverbial, but that sort of deck should in theory be very strong otherwise, so it's only right that it has a check on it. Meanwhile, those larger characters have their claimsoak removed and you can really get at their 'soft-underbelly', as it were.
To give an anecdotal example, I was playing against Bek yesterday who had her Bara Fealty with Bob out that was untouchable for me because of all the claimsoak. Going first on First Snow with 4 gold, I was able to bounce her chuds, military with Jaime, then ambush in Olenna's Informant for a second military challenge and swing it. And now she's gone up from 2x Davos to 3x Davos, because of how important he is to have out when that happens.
If you want to build/play around it though, that doesn't necessarily mean upping your curve from including loads of 3s to including loads of 4s. It can mean putting more of your effects outside of the characters (Martell, for instance, can run the icon-strippers; Tyrell can utilise Highgarden highly effectively; Baratheon's In The Name of Your King! is perfect for that round, etc.); it can mean something as simple as opening with a high-reserve plot - despite its weakness to Naval Superiority I've found Building Orders a perfect opener right now, with a strong reserve and the ability to fetch a Kingsroad or negative attachment if the opponent opens with First Snow; it can mean carefully playing characters so you never have more than you need, to minimise the impact of the plot - make your opponent always want to really turn the screws with First Snow "next turn", never "this turn", until they've run out of time to truly make it impactful.
Of course, sometimes you can plan all you like, but your deck gives you a 4-card setup of weenies without economy and you're screwed. That sucks if it happens, but as Istaril says on Beyond the Wall, I don't think it's any worse than the situation with Marched. If anything I find Marched worse, with its higher stats, far more impactful effect when it hits, and ability to be run 2x. It's just one more thing to consider, and sometimes get hurt by.
I suppose ultimately the game is always, by its nature, going to go through changes and upheaval, some more serious than others. I found it very dangerous in first edition to become too attached to any one meta, because all it takes is one new card, or group of cards, or (for first edition) restricted list change to mess it all up. Much better to be receptive to the changes, excited by the new possibilities that the cards can offer, even if those possibilities are counters for you to run when others try to focus on it!
So overall I don't find the card damaging enough to worry about, and certainly not excessively more damaging than one would expect from a new chapter pack, especially this early into the game where each chapter pack still makes up a non-trivial portion of the overall cardpool. Although I will admit to finding it intensely fun to use myself, so I'm probably biased here .