I have had my 15-22 for a bit over a year and yes, it really is a very slick rifle! It's big advantage over some of the other .22 Caliber AR-style guns is that it's operation and controls are almost identical with a "full-sized" (.223/5.56) AR so it can serve as a trainer for persons who also own one of the big'uns. It's rails also accept all the lights, grips, lasers, bipods, sights, scopes, slings and other paraphernalia that can be hung off the AR-platform. Now it can be somewhat picky about ammo but on mine there were warnings in the owner's manual about what S&W recommend, follow that and you should have no problems. I've even shot tracers with it and they work, just not cycle very well being lower-velocity ammo. As a contrast I also have a Henry Golden Boy in .22LR that is the slickest levergun I've ever used and utterly beautiful to boot! The Ruger 10-22 is a good gun and they've sold a jillion of the things but I tend not to go along with the crowd (no Hondas or Apple products for me!) and wanted a rifle that would replicate what I carried in Vietnam without costing a bundle to buy or shoot and the 15-22 fills that bill perfectly. It is not a "traditional" .22 rifle like the Ruger, but is reliable, flexible, rugged and great fun to shoot. I can't think of a better recommendation than that.
"History teaches that war begins when nations believe that the price of aggression is cheap." - Ronald Reagan