I watched the demo. It looks very good, and I think it would sound a lot better live than the demo. Why? Notice in the upper right hand corner -- You DO NOT MIC FRFR monitors. This should have gone DI to board instead. Miking FRFR monitors will always sound fizzy in comparison to a guitar cabinet simply because they have a tweeter.
Roland's COSM is a bit out of date. Line 6 is ahead of them here. Plus you need to buy a footswitch for the VG-99 if you want to control it that way.
Personally would rather have the Tyler Variax and the POD HD 500. You can do dual amp set ups like that too.
Since I'm primarily a keyboardist I love this stuff. I'm not a tube purist. Tubes do have their place, but you do have to admit that the sonic palette of traditional guitar amps is quite limited, even the MTS series. These things keep adding to the sonic palette. The more the merrier.
I can get all those sounds on my keyboards. Yes including a very very convincing guitar. Knowing how to play guitar is a plus when doing this.