I just found this thread today while browsing on a whim. And odd place for it, since this subforum is mostly about videogames, but I suppose we don't really have any proper place for tabletop rpgs on this forum.
Anyway, Fate Core. I have mixed feelings about that game. When I first read through it, I felt it was a lot more wishy-washy than previous incarnations, especially with them saying there are basically only four different actions. But, in playing Tianxia with my D&D group, I found it doesn't limit your creativity like I thought it would, and using Create Advantage is both fun and versatile.
One thing I don't really like about Fate Core is Stunt-building. It forces players to dig into the mechanics of the game before they've even started playing, and it makes you worry about whether what you're doing is too overpowered/not useful enough in the game for the points you've spent. I kind of wish they had a base list rather than just a couple of examples per skill of Stunts or at least made them more optional, since it's not a very beginner-friendly way of doing things. Also the idea that they have a certain set power-level makes them less interesting than in previous games (though I will admit things could get a bit ridiculous in Dresden Files with Powers. My were-ferret at one point rolled a +4 and, with my bonuses to Stealth for being tiny combined with that skill being moved higher in beast mode, I was able to easily reach past Legendary in my hiding attempt, and so became invisible for the rest of the scene).
One thing I've always liked about Fate is the idea of Aspects, since they're like Advantages/Disadvantages in other games, but you don't have to worry about whether you've misspent points on something useless, and the GM doesn't have to worry about whether he's punishing you enough to make sure you didn't just get some cool stuff for nothing. However, when we played, our personal Aspects didn't factor in at all (though we did use a lot of Situation Aspects). Granted, this could have come down to a lot of things, from our group being unfamiliar with the concept (we probably only Invoked and Compelled a couple of times in our Dresden Files one-shot), to our GM not being much aware of our Aspects, to the fact we only played a single session of Tianxia, and it was mostly combat, but the fact remains that the uninvolvement of personal Aspects was very much a thing in that game. I'm not saying it's a good or bad thing, but I will say that the official rules do seem to place a lot more emphasis on Aspects being flavorful and interesting and not so much on them being useful or applicable to the game, which may not be very helpful advice for someone new to the game.
Also, probably the reason why so many Situation Aspects were created in that game was just because one of the martial art Stunt-like Extras I picked for that game gave me bonuses for using Situation Aspects. One of my fellow players spent a lot of effort trying to get a consequence on an enemy so that he could use his abilities properly. I suppose this isn't really Fate Core's fault so much as Tianxia's, but I do believe they encourage you to tie Stunts to specific mechanics, and I do believe that can cause a problem of players focusing too much on mechanics and not as much on what's happening in the narrative. I suppose this problem could be easily enough solved, however, by encouraging players not to build Stunts that are set off by specific mechanics, but more by certain things happening in the story.
At some point I'd like to talk about retroclones/the OSR movement, but I'll save that for another post, since I think I've rambled on enough tonight.