Let's start with the most important thing - the vibrations are deep, strong and rumbly.
There are 3 buttons, so I don't accidentally turn on patterns (never liked them in any toy). It's easy to operate even in the dark, although I'd much prefer if it started on a slow, quiet speed instead of on 100% power and noise.
The charge holds nicely. It gets a bit weaker when the battery is low, so I have plenty of warning to charge it for next use.
It's a shame the toy is very water sensitive - you can't even operate it with wet hands. If it was more expensive I'd expect water resistance. But for this price I don't.