Trying to decide on a replacement for the Zapco ST-6 I'm currently running in my system. Currently the Zapco runs channels 1-2 to front tweeters, channels 3-4 to mids and 5-6 for rear fill. Gladen RC70 is bridged to front mid bass. I am looking to replace the Zapco because one of the channels is starting to randomly cut in and out and the upper frequencies can get a tad harsh at higher volumes. I have a Zuki 6-channel on the shelf at home but it's huge and all of my amps are mounted on the rear cab wall in my truck. Currently I am debating between a mmats 6150, more than I want to spend and probably overkill, or there is a Helix A6 in the classifieds that looks interesting but would also be tough to fit and not sure if the step down in power would be noticeable. I've tried the Arc XDI's in the past and wasn't happy with the way they sounded. I'm sure most will say get the MMATS but would like opinions or if there are any other 6 channels in the 5-600$ range I should consider.