Most DAWs these days have almost the same MIDI functionality. However, Cubase is still ahead with many advanced functions, not just for MIDI but for composing as well. To me it is still the King in the MIDI realm; If you use sample libraries you will love the expression maps for example.
Talking about Reaper, I really like it for mixing, it is very intuitive and easy, but in terms of MIDI implementation I think it is the worst of all, I find it frustrating some times to do even the most basic things.
Well that's my experience. Keep searching and comparing, I'm sure you will find the best option to your workflow.