This isn't particularly more powerful than you would expect for an amp this small. It does break up if you have it turned up medium loud and are hitting some heavy low notes. The effects sound ok but aren't deliciously high-class and subtle, and you are stuck with presets. Basically it's what you would expect and nothing more, despite the hype. I tried playing electric as well as a few different acoustics through this amp in a small room. It would be ok for a slight increase in volume for practice at home. It's a stretch to imagine this being powerful enough even for background music in a medium-small sized restaurant.
The effects are ok for a small amp but aren't as adjustable as they could be (you are stuck with about 3 different levels/types of each effect, and can't adjust these at all.)
My experience with Roland in the past is that they make their stuff very solidly, only occasional quality problems.
don't know, but a reputable company so shouldn't be too bad
For 500 bucks...you better REALLY want portability more than power and good sound quality at medium volumes. For around 250 you can get a used fender acoustasonic junior with fully adjustable chorus and fully adjustable reverb, and still have 250 to spend on other effects if that's what you need.
The Wow Factor:
It's not ugly
If you really need something that can fit in a backpack and are only going to need to play at soft to medium-soft volumes, this is probably the best sounding and most portable thing out there. Otherwise you can get a lot more for less money with other amps. Basically you are paying for extreme portability with the ac60, and don't expect it to be that loud.