I've became so addicted to this preamp I can't play my electric bass without it any more, I was introduced to it during a studio recording and the minute I plug in I knew I have to had one. Although suspicious about the lack of tweaking possibilities, I've never ever missed any, it's pretty much a plug, select a tone and play device.
Also use it with my acoustic double bass but only to take advantage of the high impedance input that is very complementary to piezo pickups, also the pristine clean sound is a must.
I've lost track of the amount of times that sound engineers thank'd me for bringing it along.
Saying that, it is perfectly designed for studio purposes, hence the (for me) cons characteristics, but a lot of musicians take it to the road.
Pros:
Easy to use
Amazing tone
Cons:
Heavy
No Power switch