Are they fun to use?

Depends on how long you can last. If you're a 3 minute quick shot then it's totally not worth it. You have to warm it up with warm water plus lubrication and when you're all done you're left with the indignity of washing your gizz out of it.

On the plus side, they can be useful for prolonging stamina. If you have a problem with premature ejaculation then you can use them to broaden your climactic threshold. Pretend that cleaning up a watery, cummy mess after three unfulfilling seconds is a substitute for shame in the sack.

Unlike masturbating the usual way, it requires an erection to get started.. Unlike a partner,it can't help you.with that,