The AER Compact Mobile is virtually identical to the Compact 60, but with one of the coolest features we know of on an amp: A rechargeable battery that gives you 3-6 hours on a single charge, and recharges on the fly when you plug it back in.
If you're someone who plays regularly in locations without power—pretty much any outdoor venue—then this is the obvious amp for you. 26 years ago I was playing my guitar on street corners in Paris, and I can only imagine how cool it would have been to pull one of these out when setting up in front of the Centre Georges Pompidou. That open guitar case surely would have had a lot more francs in it at the end of the night.
We've sold Compact Mobiles to folks playing in subways, in public parks, and even on a ski lift, but the advantage of battery power is by no means limited to busking in the great outdoors. Have you ever played a wedding where, at the last minute, you were asked to move your setup offstage to make more room for the wedding party? Imagine how nice it would be to say, "Sure, no problem," instead of frantically looking for a nearby power outlet.