I've actually just about given up on the Contessa - I love to look at it and I appreciate how well it was made and how well it was thought out for its time, but there's no compelling reason to use it. It's not great to handle, there's no great user experience and the lens is a good, but far from special performer.
I consider it to be the polar opposite to my Contax-knock off Kiev 4a. The Kiev was made by a blind guy on a three-day bender - the tolerances are way off, sharp edges hit your fingertips and forehead and the whole thing gives off a pulsating aura of crappiness. It's junk with a lens that I have never even heard of - a Menopta. But it has a bang for the buck ratio that is off the charts and it is a stellar picture-taker - sharp, contrasty, just great.
The Contessa is a jewel to look at and was designed and put together by craftsmen. But its performance and operation didn't stand the test of time, from my vantage point. If I could combine its worksmanship and the Kiev's performance, I would have a great camera. (I probably just described the M3, didn't I?)
Anywho - I have two rules. First, never keep a camera I'm not going to use and second, never sell filters because the day after I do, I will buy a lens that needs those filters.
Rule #1 probably means that I am going to give the Contessa to a friend who admires it.