The LPB-1 is just booster, very simple. I can build one in no time with very few parts. Very easy to clone and has been countless times. There's better boosters out there.
The Micro Amp is a better circuit, IMO. It's a lot quieter and has a much more natural sounding boost to it.
However, having said all that, you should try them both for yourself and then decide. Check out the MXR MC-401 too, I've heard good things about it. Need to try one myself one of these days.