I called Roland the other day and got a very helpful rep on the line. We talked about the GW8 and the 330 and the 300.
His views--I'd miss some of the real time features (Buttons) of my G1000 if I went to a GW* -weight being the only big advantage.
On the 330- great small amp but really designed for small outdoor (battery) gigs for an acoustic gutiar or what ever. It may be good for arrangers in small situations. I'm still probably going to get one.
On the SA300. Forget it without the matching sub and as stated the sub is so light you may as well bring it. Not really for my Hammond XK3 but good for arranger/vocal in a small/medium situation. Two of them would be killer.
He sent my # to the East Coast sales rep to see who had one I could actually hear. Waiting for a call

Bill in NJ