I switched from an older Denon receiver to the Outlaws and kept the Denon as a pre-pro. I don't know the 5800. I thought the sound was cleaner and fuller with the Outlaws. I actually bought the Outlaw 950 but sent it back. The controls were clumsy and it was noisy. I think the pre-amp in the Denons are very good, but the Outlaw amp is a better amp and is conservatively rated at 200 W/ch.