Different...in a very good way
Strats and Teles are everywhere, and Les Pauls and SGs are fairly common, too -- but you don't see many Firebirds around. That alone is no reason to get one; the guitar has to work for you. The Firebird is a different beast, and it definitely works for me.
This is the second one I have owned; the first was a non-reverse Studio version with three P-90s. I didn't like that guitar -- headstock dive, wasn't comfortable to play, the middle pickup got in the way of my picking...so I was a little reluctant to get this one. But I absolutely love this Firebird. It is well-balanced, with no headstock dive (is that bc of the Steinberger tuners? I dunno). It looks iconic and unique at the same time. The mini-humbuckers sound really good; many describe them as sounding somewhere in between a standard 'bucker and a single coil...that seems about right, although definitely closer to the humbucker end of the continuum. Comparing them to Les Paul pickups: not as beefy, not as dark -- but still unmistakably a humbucker. (I bought the guitar assuming I would upgrade the pickups, because I almost always do -- I hear Lollar mini-buckers are great -- but I actually like the stock ones a lot. For the time being, at least, they're staying.)
The neck is terrific -- a little wider than on my Les Paul, which at first I wasn't sure I would like, but after just a few minutes I adjusted to it, and now it's my favorite neck. It's really a fast neck. As others have noted, it's a long guitar, and while the neck length is standard Gibson 24 3/4 scale, it definitely "sits" a bit more to your left than other guitars -- i.e., your hand will be extended out a bit further when fretting around the nut. That, too, requires a bit of getting used to, but once you do, it feels natural again. The way the guitar sits also puts the upper register of the fretboard in a more accessible position, so I find myself playing up there a bit more, which is nice.
The finish on mine is immaculate, and set-up was terrific right out of the box. This is the only guitar I have ever bought (and there have been many) on which I haven't changed or adjusted a thing. (Wait -- not true: I did put on strap locks, and you should too -- drop this thing, and you will bust the headstock.)
Sweetwater was terrific to deal with; I never, ever buy new guitars, but I did from them. The price was low, sales staff was really knowledgable and friendly, and shipping was quick -- it arrived 2 days early!
The Firebird isn't for everyone, but this one is a great guitar for those seeing something a little out of the ordinary.