I joined a campaign that played a few times before. I've only played a few times, but the campaign I joined had played much longer.
The system is pretty good, although it takes a bit of doing to get into the rhythm. The doom and momentum systems compliment each other fairly well, but players need to know anything that requires more than 3 successes is virtually impossible without a ton of help or spending a session token (forget what they're called... like bennies in Savage Worlds). It's very pulpy, but failure can be rather high-cost. So, yes, the mechanics suit the game setting very well, IMO. The only thing I don't like about the setting is that there's like two dozen languages and none of them are ubiquitous, and that's just irritating to me to keep track of it all.
There's a lot of gains in the system to be made just by player system mastery and sometimes it means the players take actions just generate momentum for other players. The initiative system is critical, because the PCs need to be able to order their turn correctly. You need players willing to work together and make a plan each round. It's much more cooperative and collaborative than D&D is in that sense.
For advancement, you end up spending a ton of experience on the lowest tier talents, firstly because they add a lot of value, and secondly because the discount you get for expertise means they're very cheap. Talents that give you extra momentum, die rerolls, or extra successes are gold. It feels like the game goes through a few phases: 1) buying cheap talents with high value, 2) saving for more expensive talents, 3) saving for skill increases, 4) saving for stat increases. We never got through phase 2.
Personally, I'm not a huge fan of the fact that you have to buy focus and expertise separately. Skills are already absurdly expensive to raise, and it seems very fiddley to not just keep them as one stat.
Character creation suits the setting, but it's not remotely unusual to end up with a character who is good at nothing you enjoy because it's all random. One of our players rolled an archer and just hated it until he changed characters. I would expect to let people roll 2-3 characters up and then pick one. If you let someone just pick instead of rolling, however, they could really min/max the game to an absurd degree so it feels pretty important to use random generation to have organic characters. In that way, I'd be cautious about using the Weed of Sorcery rule unless you really want a powerful spellcaster (although weak spellcasters would not be very fun to play, IMO).
You'll discover the book is pretty terribly organized. That is, the book is largely written from the angle of how to create a character, not how to run or play the game, and it shows. Several times in just the sessions I've played I've wanted to find a table or paragraph I knew existed, but they seem to be scattered throughout the book and you'll find yourself flipping around more than feels necessary. It often feels like a critical rule that relates to two or three parts of the game is only mentioned on one line in one paragraph in one section of the book. The rules are also not concretely written where you'll wish they were, but you'll figure something out that works.
Magic is devastating, but very hard to use as a game mechanic. I rolled very lucky on character creation and ended up with a very good Sorcerer. The very first session I was able to keep up with the rest of the party in terms of damage, and they had played quite awhile. Magic rules, however, are very, very fuzzy and confusing. I would recommend against allowing magic-using characters for the first campaign or one-shot because you've already got a ton to learn. Expect to have to fudge magic a lot, and I recommend being flexible like the spells in Savage Worlds. There's a
magic FAQ that if you dig into it you'll see that it was written by the game's designer and I consider that document 100% essential. It adds a lot of necessary context and clarification because many things in the book are just plain wrong or so misleading that they're basically wrong.
Finally, there is
an official character generator. I'm not a fan of using it in actual play, I did like being able to generate characters repeatedly to see what you end up with before doing it for the actual campaign.
Unfortunately, I can't really tell you about DMing the game as I never ran it.
