simple, 770. I looked for several weeks and read all kinda reviews and listened in a few high end shops. But, after reading a lot of the reviews that the amp is subjective to listner, speaker pairing, and type of head unit, I figured that for the money and the 30 day trial, to give the 770 a shot. Once I did, I was happy and never regretted it. Also, look at the price of the 770 for the features it offers. I will take more AMP power in a heartbeat if the two price points are similar as are the rest of the features. Granted, the 770 is overly simple in features, it fits my build. And double the power really makes itself known in the low end on my full range 8 ohm Infinity's. I upset my wife even more with the new amp