Honestly, if you are coming from that legendary EF 85mm f/1.2, you might find the native RF options a bit of a shock to your wallet. Since you have a wedding coming up fast, be careful about switching systems completely. I would suggest picking up the Canon RF 85mm f/2 Macro IS STM instead of blowing the whole budget on the L-series. It is super sharp, light, and the image stabilization is a lifesaver when you are shooting handheld in lower light. Make sure to factor in that you can always use your existing EF glass with the Canon Mount Adapter EF-EOS R if you need that f/1.2 look. Dont rush into expensive native glass just yet until you test the adapter out on your R6 Mark II.

Honestly, grab the Canon RF 85mm f/1.2L USM used if you can find one. Its pricey but in my experience, nothing beats that native glass for weddings. Dont risk an adapter.

At Reply #1 - good point! Using an adapter is an option but it changes the balance of the camera, especially with those heavier L-series optics. Honestly, moving to a new body for a professional gig is always a bit stressful. Before you drop two grand, have you considered renting a couple of options for a weekend? Places like LensPimp or Hireacamera are solid for gear testing here in the UK and it saves you from buyer's remorse right before a wedding. Are you finding that your current EF glass is struggling with the autofocus tracking on the new sensor, or is it more about the weight and size of the adapter setup bothering you? Sometimes just updating the firmware on the adapter makes a world of difference for those wedding shots. Also, are you strictly looking for that classic 85mm compression, or are you open to something like a 50mm if it gives you more flexibility in cramped London venues? It might be worth checking the MTF charts on the Digital Picture website to see if the sharpness drop-off you're worried about is actually noticeable at the apertures you usually shoot at for portraits. Its worth figuring out if your issue is optical performance or just the ergonomics of the new system before committing to a native lens purchase.