Just got this amp in the mail yesterday,had it installed the next day it sounds much better than my Gravity 100 x 4 channel.This thing sounds louder and clearer for being 80x4 channe. Theres only one minor glitch for me that is and thats the control panel on top of the amp the buttons are in a perfect place but i think the plastic cover over the panel should be able to slide cause you have to use an allen wrench to take 2 screws off .And the other is the buttons i couldnt find anything to turn them they have a groove in the shape of an arrow they stripped a little with my flat screwdriver i just need to find the right gadget to turn these buttons with. I think they should either pop out or have a smaller deeper groove thats my opinion just being honest.But overall this is propbably the best 4 channel amp i have ever purchased. I purchased this amp for$ 195.00 out the door free shipping i used the memorial11 code this amp runs $449.00 and add $50 for taxes and not to mention i have a pair of 15 inch mbquartz reference subs they hit hard i have had them for 2 years still bumpin .