It's taken me a lifetime to get here, but I would take a Rolleicord over a 2.8F or GX any day of the week. The Rolleicord won't have the EV interlocks. The Rolleicord will be much lighter. The two take essentially indistinguishable photographs. The Rolleicord, lacking the complexity of the Flex's automated film advance and shutter, is less prone to damage over time. Rolleicord accessories are plentiful and inexpensive.
I used to shoot 2.8E2 Rolleiflexes most of the time. (To me, they were the apex of Rolleiflex design.) But now I shoot a Rolleicord II with a Triotar lens, and an early Automat with an Opton Tessar lens. They do everything I need from a camera.