Funny how Tricams seem to divide the world, east coast/west coast, traditional (or noob) from sprad, etc. Some folks swear they "never leave the ground" without their pinkie. Then again, some folks carry three belay devices with them at all times. Heck, there's at least one person out there with a pink Tricam tattoo. I've heard people talk about carrying doubles, even triples of the pink.
I do like Tricams. Sometimes they fit in places that cams and won't. Sometimes they allow me to carry fewer cams. On multi-pitch routes I might build the belay mostly with Tricams and let my partner have the similarly sized cams for the next pitch. And Tricams take the place of big nuts or cowbells. Oh, I mean hexes.
Yes, Tricams can fix. I lost one on the Original Route on Whitesides. I was way run out (on admittedly moderate ground) and getting tired. I found a solution pocket that would take a pink. I jammed it in, set it, and wrote it off. I knew my partner (mostly a boulderer) would never get it out, but having the protection was worth it.
I carry from 0.25 to 3.0, and in my regular circuit at my home crag, I will place them all multiple times in the course of a day.