I have a Perkeo II with the 80mm f/3.5 Color Skopar and an Ercona II with 105mm f/3.5 CZJ Tessar; 6x6 and 6x9 respectively. Is the final result as good as my Bronica SQ-A, no, but honestly, for a typical photo how often does it really matter? If the central point of the shot is in sharp focus the eyes aren't doing microscopic analysis on the corners. Sure, I can think of some things where I'd want the best I had -- and then I'd use the Bronica. But alas, the SQ-A does not slip into my jacket pocket!
Yes, IQ = Image Quality. In cameras, a high IQ is not necessarily smart!