I've used a Rolleiflex T for years and have been very satisfied with the quality of the 3.5, 75mm Tessar lens. It's not just a case of sharpness, there is a extra what I can only describe as "roundness" about the quality that makes it stand out from anything produced by 35mm or digital.
Once you become used to the reversed image in the viewfinder, you will love the large composing screen, and learn to take your time composing your picture. This will make you a better photographer. as it will slow you down, making you more discriminating over what you take, with fewer pictures, but they will be of far better quality.
Do try and develop your own black & white negs., once you settle on a development technique, you will bring out the full quality of your camera. Except for colour tranny, I process my own, since I've increasingly found lab quality erratic with negative material.