Amplug is perfect product to me somebody can't have bass amplifier in a small house. Using Amplug, I can practice without bothering other people by loud and unblockable low frequency sound from bass guitar and I can still have good quality sound during practice.
You can get awesome amp-like sound by using it with good studio headphone (mine is AKG K240S) without complicated parameter set. Built in drum patterns are really useful when you need to play with metronome (but no pure metronome mode available, all the 9 types are drum). fold-able plug design let it be compatible to most of bass model types. But don't forget to remove Amplug from bass before you put back you bass on stander or gig bag after practice.
For cons, I did found the apparent hum noise during operating as other review describes. I have tried to mute bass by knobs on my bass but it still exists. Apparently it comes from circuit design, not from bass. To avoid it, I suggest to turn the vol control low under "6" if possible. To elevate bass hearing volume, try to adjust from gain mode. High gain - low volume get low hum. Now I am comfortable without hearing hum during playing. Another cons as I mention above, no pure metronome mode can be selected. For some specific situation I think I might need to practice with pure metronome because too many note from real drum pattern sometimes confuse me.
By the way, I also tried to use Amplug bass with my guitar. It's amazing! It sounds great with fascinating texture especial with single coil pickup. That surprised me more than use with bass!