Being of the male variety I’ve got some extra gubbins back there for which the vibrations work well.
I’ll usually lube it up, put it in, find a speed or pattern thats working and leave it at that.
Initially its a nice enough feeling but doesn’t do anything spectacular. However as I approach orgasm, internally things start to move a little bit as I get harder and suddenly, its in the perfect position exactly when I need it. I don’t know if its hitting my p-spot or just the nerves but thats when it becomes spectacular.
I find silicone more comfortable but metal more controllable.