I gave up on rollei qbm for film usage after a few years because beyond the lens mechanical problems the bodies are all really awful and prone to issues - the last of the mechanical ones the sl350 is priced higher and worth it for the better viewfinder
both the zeiss and schneider 50 1.8 lenses are wonderful with great thick line contrast and punchy imagery even wide open, probably the best value in the system
If I absolutely had to shoot rollei qbm lenses I would buy the few slightly rarer versions that were made in m42 mount and shoot them on a spotmatic or chinon or anything but the rollei 35mm slr bodies which are somehow worse handling and more prone to issues than even the cheapest japanese SLR - I don't think the entire product range was made this way but there are at least 50 1.8s and 35 2.8s like these listed on ebay , linking to random auctions of these here - these examples below are not the mamiya made rolleinar stuff but the zeiss designs
50 1.8 with voigtlander badge , same lens as the qbm 50 1.8 planar
35 2.8 with voigtlander badge, same as the 35 2.8 distagon for qbm
the names get confusing because the product lines were a mess with tremendous overlap at the time - there are also voigtlander rebadges of the mamiya made lenses as well which share similar names but added AR and feature the same barrels as the mamiya made lenses for the QBM system
compare with this voigtlander badged mamiya lens for qbm for example
all in all, for collecting, adapting to mirrorless for "character" and shooting once in a blue moon the qbm lenses are great, get a clean sl350 if you can find one for a good deal ($200)
but I would advise against them for shooting regularly other than the option of using the m42 versions on better bodies
obviously i'm only stating all this from my own experience, maybe somebody else has had a better run with the bodies and lenses but for me it was heartbreaking stuff, I was quite happy to give my qbm lenses away a few years ago - with that said if there was a good way to shoot that 50 1.4 planar with it's pleasant rollei reddish color rendition as opposed to the contax i would be happy to use that lens for 95% of my color 35mm photography but sadly there isn't