I just did give you the downsides.
It's not a fast bike, so if you're scraping the pegs, then you're going into the corner too fast.
I've managed to scrape the pegs as low as 10mph before in a lovely slow turn.
Looks crap if you don't polish it.
Custom accessories cost a lot.
They are usually quite heavy.
They are only ridden by Rockstar wannabes, posers, tossers, posing tossers and hard-as-nails 1% Outlaw bikers.....
I'm trying real hard to come up with real bad sides, but there aren't that many, TBH.
Maintenance is usually great, as there's no fairing or anything in the way.