I believe it's the Rocker 30 that ebenex have stock on, well of course besides the wattage difference, rocker 30 does not have reverb feature unlike the rockerverb 50. In terms of sound, I would say they share similarities in tone, but of cos u will expect the 50 to have larger headroom. If your aim is mainly for home use and small gigs, the Rocker 30 will suffice the need, but if u are looking to play on the big stage or playing loud at home is not an issue, the rockerverb 50 will definitely be the machine to go for.
With that said, do head down to ebenex to try out the rocker 30 and get the feel of it and see if that's the voice u are searching for.