Well first off let me just say I DO like ampeg 810 cabs. The best rig I've played through was an Ampeg 810 with 2 Sansamp RBI and a power amp. That rig hit HARD
The reason I went with GK and will stay with GK is I love the RB series tone... with the boost cranked you get an almost tubey response. The controls are easier to use the the AMpeg SVT heads. I also messed around with an SVT 4 pro / 810 rig for about an hour and I couldn't get a tone I liked. I was very underwhelmed.
With my rig now, the range of what sounds great is massive and I can easily adjust for the room I am in.
I will also say that the GK stuff doesn't color your tone like Ampeg.... which is all preference really. O and new the GK stuff is cheaper
When I start playing bigger venues, I wil move to the NEO series cabs since they have a MASSIVE sound, right now I'm using the MBE cabs and they have a HUGE sound



