Take a look at the Leupold TBR 1000i.
I have used several Nikons, The best was the old Monarch 800 - but it would not do cuts. My rifleman 550's were OK and did the cuts fine. The Leupold is a huge upgrade and IMO is much better than the current Nikon offerings. It is very accurate, repeatable, has a great optic, ranges stuff all the way out to 1000 like it should, has a bow mode that's good out to 100 (would prefer more, but it will still give you the angle). The red display inside is awesome in low light and has 3 settings for brightness depending on ambient light. Nice small package that fits well in your hand too.
I'm very happy with it and I HATED the original Leupolds like your RX-IV. They SUCKED - especially for archery. The engineer argued with me that the program was correct - she did not understand the way bowsights worked so she was all messed up. It was up to 4 yards off which as you know does not cut it for archery. They finally got it right with this one.
Coop