I was/am a trumpet player, and on a whim, for fun, I experimented with a borrowed valve trombone, and loved the fun of it. This was a terrible quality instrument, in very bad shape. So I went and bought this Missenharter in a pawn shop in New Haven. I played with this valve trombone at Yale med school for almost the total 4 years, with a small combo, usually drums, piano, upright bass, baritone sax, and me. We played without "charts", tunes that we knew or learned, at first for fun, then small "gigs" for free, then, when the requests came so frequently, for a modest fee. Our best, biggest job was being the back up band at the Yale Senior Prom in Payne-Whitney Gym in  my last/senior year . 

After graduation, in Internship, Residency, then Vietnam, I played very infrequently, sitting in with other groups that were playing at the social thing we were attending. This was, at most, 2-3 tunes, as per my wife's "suggestions". This usually was our only night out in many days or weeks, as my on call schedule was brutal. Playing more was never a consideration. Since that time, I have essentially reverted to trumpet. 

Now, I am considering playing this trombone again for fun, with my two grandsons who play trumpet very well.  And who knows--- it might sound good -- or not. You never know until you try it out.