Yeah, the Shotgun is somethin I gotta get back into habit of usin, too.
Though to be fair to the flaregun, I did make some excellent use of it the other day against a Heavy who was keeping his gun spinning up to try to pick me off at range while I was carrying the Intel. The mini-crits it gives at-range to burning targets are damn handy; I forced his HP down fast enough that he switched to his Sandvich, and I rushed up and ignite/Axtinguished him to death while he was eating. Proceeded to die to a Shortstop Scout just around the corner, though.