I just picked up a Leica 2400R from Doug at Cameraland and I’m pretty impressed with it. I researched quite a bit and for the money I think it could be hard to beat.
It really depends on what you do with your RF and what you hope to do, and how much you want to spend. Definitely look at Leica products, fantastic glass, great ranging, lots of choices, which is best for your depends on your wants, needs, and plans.
Sig is another to look at. They have a ton of choices to fit various budgets. As you go up the ladder, you add more and more functionality. Very advanced in their features.
Both of these manufacturers allow you to input a custom curve on some of their models, enabling them to provide fast, accurate ballistic solutions. Some others do as well, while others require you to choose from presets.
There are lots of factors to consider, glad to help if I can, I have a few reviews on here covering the Leica 2700 and a prototype 2800, as well as one on the Sig 2400 BDX. Feel free to check them out and/or PM me if I can answer any questions.