I have got my Roland Cube 80XL and I am quite pleased with the purchase (thanks Elantric!)
I have not even scratched the surface, but here's my comments based on my 1 hour of fiddling with it (at bedroom levels).
1) Pretty intuitive amp and tight low end!
2) Nicely written user manual gives you everything you need to know about the amp- crisp and clear
3) Pretty compact for 80W size and looks sturdy with corners protected and a metal cover in the front.
4) I tried the aux in input with my Godin LGXT and GR55. Sounds very nice- much better than my Tech 21 PE60. The disadvantage of running your GR55 in this way is that you don't get to control your amp at all. Volume or EQ controlling is not possible on the amp.
5) I experimented a little bit and connected the GR55 to the input channel of the amp too. With this you get to control the EQ and volume using the onboard knobs on your amp. I got a sweet acoustic sound with my acoustic patch on GR55 + the acoustic sim model selected on the cube 80XL, just with a little bit of EQ tweaks. I kept the gain knob on the amp low and raised the volume.
6) For the electric sounds from my GR55 (cleans as well as dirty), I switched to the JC clean amp setting on the Roland cube 80XL (this is quick with the press of a button). Presence on 0 and EQuing helped me get my tones sounding real nice!
Mind you, this test is just at bedroom levels, I can't wait to go high on the volume and test everything again.
So far, excellent and a versatile amp..worth every penny and I don't think I would need any amp for my GR55 soon!!...