I've been using this looper for over a year now. It has some bad issues.
First off, recording over multiple times reduces the sample quality dramatically. Especially if you're recording in lower frequencies and\or distortion effects. It's very frustrating, as it kinda looses it's purpose without the feature to record over.
Second issue, it has some weird filtering issues. Some of the effects sometimes get canceled out by the looper pedal. My tremolo effect does not work with this effect.
It has a nice feature though, you can extract recorded samples through usb port to your pc. However, the software for that is only written for windows. So if you're using some other system, you're out of luck.
The thing that i do like about it, the control is very simple. You can record, delete, stop, play and cancel using only the single switch and a combination of taps.
All in all, it's a good toy for the price, but I strongly recommend to look for a better investment