It was ok. Not quite a Marshall. I preferred my boosted JMP. I honestly thought it sounded similar to a Mesa Mark (I know the circuits are not related); maybe it was the smooth tone and touch responsiveness. But I preferred the Mark for its chugga chugga ness. I never tried boosting it.
It seemed fine and works for just about anything type of high gain tone. It just didn't wow me.
I liked the normal channel on the SLO30 cranked and boosted. Overdrive channel was tubby for my use. For whatever reason, the Synergy SLO module has been my #1 since I picked it up a few years ago. It's tighter and has more usable gain.
The SLO has so much control I could make it sound like a Plexi by turning down the gain and turning the volume up. The SLO is probably the loudest amp I’ve ever played it will peel the paint off the wall