I was going to have my rollei cleaned and repaired back to specs before I realized after taking it out of the closet that not only is there some sort of fungus between the lenses, the film transport is off, but the cable release thread is also missing (purchased cheap to play with). After receiving some inheritance money I test shot a hasselblad and a bronica with chromes and borrowed a high power schneider loupw from a friend (10x I believe). Using the latest bronica 80mm lens (the PS) and a one generation old hasselblad (the name eludes me at the moment, but it was a T something and it was black) 80mm lens I couldn't tell any difference at all in the center nor the edges once I hit f/5.6. At f/4 I thought I could see a difference, but I wasn't sure, but at f/2.8 the 'blad lens was sharper in the corners, but not enough to justify the price difference to me. I purchased the SQAi and have been loving it. If you'll check the prices at KEH you'll see that you can pretty much buy a 50, 80, 150, 250 lens set for the Bronica for the price a 'blad 50mm will set you back. I can outfit myself with the 4 lenses I anticipate using, 4 backs, a polaroid back, a WL and prism finder, and two bodies for under: $2500. That's even better than you can do in most 35mm systems! I purchased my initial set (SQ-Ai, WL finder, 120 back, and 80mm lens) locally from a gentleman who moved to digital and borrowed the hasselblad from the friend with the loupe. But all of my prices from www.keh.com where I buy a lot of my used equipment. Their used prices are near ebay's and you get a 60 day warranty and 7 day return window and the guarantee of actually receiving the product.
disclaimer: no, my test was not done in laboratory conditions nor checked against l/mm charts, but I don't shoot in a laboratory nor do I shoot charts for my normal photography. I just shot a roll each outside of a stationary object from a tripod with mirror lock-up on an overcast day through the range of apertures and subjectively looked at the results. In the end I knew I was going to buy the bronica just based on the $$$ factor, but I wanted to see how much quality I was going to give up and the answer is very, very little. At the sizes I hand print (11x14 and under, usually around 8"x8") I don't ever anticipate that any difference in quality could ever be seen--at least by me and that is what counts to me. In my opinion, with today's computer tested lens models any modern lens will perform well enough for 95% of people and 4% of the others shoot with older lenses for the je ne sais quois they bring to the image. When you add the increase in film technology you really shouldn't have a problem. If expenses are a factor and you don't care if people see you shooting with a bronica (some people HAVE to shoot with a hassy or a rollei and I'm not knocking those who actually use their equipment, but I'm sure we have all met someone who wields their gear as a status symbol: i.e. the colored hasselblad bodies or the special edition leica cameras) then I say buy the bronica with a couple of extra backs and lenses that the savings over the hassie will net your wallet and just go shoot. In a few months you will wonder why you even cared what camera you purchased, it's not about the gear, it's about the images. </rant>