I have ETR, SQ and GS-1 series cameras and lenses. The early 150/4 MC for the ETRs is supposed to be a weak performer but I like mine. In the SQ series I have the 150/4 PS and the earlier 150/3.5 S. Both are very good. The PS has better coating so in difficult lighting situations more care must be taken with the S. The 50/3.5 PS is very sharp. I don't see a big difference between the 80/2.8 S and the 80/2.8 PS. They are both very good. I have the 105/3.5 lenses for the ETRs and the SQs. Both are good but the main benefit is that they allow closer focusing for portraits. When Bronica went to the P series of lenses both were discontinued. Lately I have been shooting more with the GS-1s. I am using the 50, 65, 100 and 150 lenses. I wish they had closer focusing but they are all very good. The GS-1 seems easier to use hand held than other 6X7 SLRs. There are plenty of good lenses for 35mm use. There is also good 35mm film to go with them. The main advantage of a medium format camera/lens is that you don't have to enlarge as much. To make a minimally cropped 11X14 from a 35mm negative you have to enlarge 11X. The same size print from a 6X7 negative only has to be enlarged 5X. There are lenses for 35mm cameras which are sharper than those for medium format cameras but they are not more than twice as sharp. Even with Ektar 100 you will see a difference between enlarging the film 11X and enlarging it 5X. Cropping down to 6X4.5 from a square negative will make me enlarge just more than 6X to get the same 11X14. It all comes down to how large a print you need to make. Bronica GS-1 equipment is much less expensive than Hasselblad 6X6 equipment. Last week I got a GS-1 body with no crank or focusing screen but with the battery door for $17.16. I put on all of the necessary parts and the camera works as it should. I just bought a second GS-1 plain prism finder for $50. Now I have two working GS-1s. A third body needs a little work. With a GS-1 and a roll of Ektar 100 I can make prints as large as I like. I have been lucky because most of the Bronica equipment I have bought works well. When do I use the SQ cameras? Mostly when I want to carry something light: SQ-A body, 80/2.8, crank, waist level finder and back. I have a Speed Grip and prism finders for my SQ cameras but when I know I will be shooting verticals and using the oblong format I use an ETR or GS-1. I consider Bronicas the best bargain in used medium format SLR cameras.