I've used carboys for every batch I've ever brewed except for one , my reasoning is ...
Glass doesn't scratch and harbor bacteria
The shape of the carboy reduces headspace
It's easier to get a good seal
I hook up a blowoff tube for the high krausen stage and it will naturally remove excess fusels and bitter resins
I can harvest yeast from blown off krausen
I can watch the yeast work and judge when fermentation is complete with out a hydrometer
I could probably come up with more ... this is just top of my head
Oh and there quiet ... the one batch I did in the bucket sounded like a marching band ... could hear it all over the house ... Bloop ,bloop ,,bloop
Reasons against would be weight and possibility of breakage ... neither bother me ... I can lift heavy things.