I'll forgive the "vinyl" business --except for a few, they ain't vinyl but rather, shellac. Which is why, incidentally, you don't want to clean them with an alcohol-base solution: they'll melt!
Soundwise, they're all over the map. Some are really extraordinary, but most are not. Somehow, though, even the lesser ones can have a magic that draws you in while you listen through their limitations. Then, of course, every 3-4 minutes, you have to get up and change the record!
I have a parlor trick that never fails to amaze. Put on an Artie Shaw Gramercy Five CD and follow it with some of the same tracks on 78.
There's absolutely no contest about which sounds better (although it helps that the CD is one of the worst-sounding ever made).
There are tricks to reduce or eliminate surface noise, and the better the turntable setup (I use a 1962 Empire and Grado 78 cart), the better they'll sound. You can even tell the difference between turntable mats.
I have an old Victrola too and it IS fun to listen to. But there's a lot more music on 78s than most people think, and it's worth trying to make the most of it. Dave