The 800.4 is a tad bit longer than the 1800. My 800.4 has served me well with no complaints and I have yet to use more than half of what it is capable of
Yes the 800.4 is just as long as an AQ2200. My 800.4 has been great. I did thermal protect it one time. It was at the beach in my closed trunk and playing music for hours at 2ohms per channel full tilt.. lol