The lens on the 35SP is legendary. Along with the spot metering and the full metered manual mode, this is generally recognized as one of the best RF's ever made. The pictures from mine are sublime. But after running a number of rolls thru it (plus the SPn, UC, RD, DC, etc. etc.), they all went back on the shelf and I'm back with my OM's. The RF's just can't compare to the versatility of the SLR, and I always found the 40mm FL a bit odd. You wouldn't think it would be that much different from my favorite 35mm, but it really is noticeable in terms of composition.
My biggest beef with the RF's was the long, stuff shutter release that was required to trap the meter and set the aperture. I would get pushbuttonitis after a day of shooting, and you never knew exactly when the shutter would snap. This caused a big problem with camera shake and resulted in a number a blurred shots (something that is never a problem with the OMs).