I had the opportunity to use a Swaro, Vortex Razor HD, Sig, Maven and two Kowas over a multi-day long-range hunting course and this is my ranking based on a subjective mix of clarity, brightness, and general "how did I like staring through it for hours each day" factor:
1. Kowa TSN-883 (and the tiny 553)
2. Swaro ATS-80 (Kowa 883 edged it out on brightness -- otherwise both were identical)
3. Maven S1
4. Sig Oscar 8
5. Razor HD 85mm
All were good to easily assess impacts at 1k yards, but there was a healthy step up from the Razor-Sig-Maven group to the Swaro and Kowas.
After the course ended, I was so impressed with the Kowa that I ended up ordering the 553 and have continued to be extremely impressed, especially considering its microscopic size. It obviously will never gather as much light as the larger objective options, but if you can get away with it, then I would strongly consider it. I know these aren't 65mm, but hopefully this can aid your search.