Just for curiosity, what is wrong with the CMM4? We exclusively use the CMM4 rackmount now. After too many years of worrying about damaged equipment up towers from lightning strikes, I have moved away from tower mounted gear as much as I can. Not to mention far more switching options, gigabit to each radio, eliminating that single point of failure, etc. I also really like the dual power and now capability to power the 450i gear without issue. I love them.