I was looking at some MF stuff just today at KEH. I always wanted to get into either a Pentax, Bronica, or Mamiya 645 system or the Pentax 6x7 system but never had the scratch. Now it looks like any one of those systems is well within reach at about $1000 or so with one lens, back, body, prism, etc. I hesitate though because I just wonder if there would be anything to be gained in image quality over what is currently available in the 5D3 or even my current 5Dc. I love the cool factor of having an old-school, manual focus 645 or 6x7 and even going so far as metering manually but I don't want to make the mistake of sinking a bunch of cash into this if it's just a passing phase for me and I won't stick with it because the IQ advantages just do'n justify the expense. Any input?