p.1 #1 · Who has used Canon RF 85mm 1.2 L and the RF 85 1.4 L ?
At the moment, I am hesitantly selling my Canon RF 85mm 1.2 L lens. And the main reason is downsizing weight and size. If I sell it, there must be an 85mm replacement because that's my favorite focal length even if I don't shoot 85mm a lot. If I stick to a Canon lens, my primary options are:
Canon RF 85mm 1.4 L
Canon EF 85mm 1.4 L IS
Canon EF 85mm 1.2 L ii
I had owned the EF 1.2 L ii for several years. And I still think it was a nice lens despite quirks. Even better yet on an EOS R body. It's not perfectly balanced on an adapter, but pretty good. Actually, I also owned a Tamron 85mm 1.8 VC at the same time and that was a very nice lens. But I'm thinking it's safer for compatability to stay with Canon in the long term for EOS R bodies.
Anyhow, I haven't had any experience with the EF or RF 85mm 1.4 bodies and don't know the pros or cons of those.
p.1 #2 · Who has used Canon RF 85mm 1.2 L and the RF 85 1.4 L ?
I've owned many 85 lenses over time, including the legendary EF 85 1.2 II, but also the Tamron 1.8 you mention and the EF 1.4 L.
Althought I've never owned the RF 85 1.2 I did shoot with it. Fantastic IQ and a very unique look, but indeed big and heavy. Currently I have the RF 1.4 VCM lens, and I think it's great. It is very light, compact and the AF is incredibly fast and accurate.
Image quality is very good too: sharp even at 1.4, and the images produce a very nice bokeh. That said, I do think you'll notice a difference with your RF 1.2, being that images produced by that lens will feel a bit more 'magic' or unique even. A reason why (for now) I'll keep my RF 50 1.2 and not trade it for the 50 1.4 VCM.
If size and weight however play a role (it does for me), then the best option would be to go for the 1.4 VCM. The EF options including adapter will be much bigger and heavier.
p.1 #3 · Who has used Canon RF 85mm 1.2 L and the RF 85 1.4 L ?
The ultimate RF 85mm lens IMO is the AF Samyang RF 85 f/1.4, if you can find one. I bought mine before they were banned, and I love it. I can't help myself from buying fast primes so I eventually caved and bought the RF 85 f/1.2 and used it for awhile, but as I suspected the Canon RF 85 stayed on the shelf while the Samyang always made it in the bag due to size and weight. Ended up selling the RF 85 f/1.2 and I'm still using my Samyang 5 yrs later. I've used it on my R6's, R3's R5's, and now R5II's. It's super lightweight, even a tad lighter than the 85 VCM, but it's a bit fatter. Anyway, I love the rendering from the Samyang and if you can find a good one they can be had for under $600. Otherwise, the 85 VCM is a great lens and will be your only other option for a small/lightweight fast 85. Older EF versions will require the adapter which adds length and pushes the weight away from the camera.
p.1 #4 · Who has used Canon RF 85mm 1.2 L and the RF 85 1.4 L ?
I own both and both lenses render fantastic images, so you can’t go wrong with either!
The vcm is a tad faster in AF which might be of importance for fast action , so more keepers: VCM glass is FAST.
Both lenses are extremely sharp wide open.
The 1.2 is HEAVY and much more expensive!
the best bang for the buck is the vcm in my opinion
p.1 #5 · Who has used Canon RF 85mm 1.2 L and the RF 85 1.4 L ?
In terms of image quality, focus speed, usability, versatility... everything, really, the 85 VCM is the nicest lens I've ever used. I'm selling mine only because my 70-200 Z makes it functionally redundant for what I do, but had I not purchased that, I'd keep the 85 VCM forever.