The original posting was related to the 645 format and camera. I the MF realm I've used up through 6x9 but for me anything larger than 6x6 is too large as a walk around and handhold shooter. Even 6x6 and 645 I tend to use a tripod for about 90% of my shooting. I do like the Rolleiflex as a walk around but most other 6x6s including the SQ I find a bit too cumbersome. The 645 ETR is so flexible with the ability to go from a simple light SLR to a loaded tank in both 120 and 35mm wass the answer for me as I am not into having multiple systems or at least that is what I tell my wife.