So, you must have a Mat with a Yashikor lens; one of the models with the Yashinon lens, like the 124 or 124G, might give you better results. You could also consider a Minolta Autocord. I have both, and prefer the 'Cord. It's a fine piece of gear, and ergonomically is IMHO the best of the TLRs.I have been toting around a Yashicamat. I am getting weary of the single coated lens that is not sharp below f5.6
If you want cheap.......... I picked up an Iskra, a Russian camera which is a knockoff of one of the later Zeiss folders. It's a 6x6 with a coupled rangefinder. Build quality is not great, but so far I've had no troubles with it, and it actually is capable of very sharp pictures. I paid $45.00 for mine.