I'm sorry that no one answered your question. Red was hit hard with nerfs for a while making Lightning the one to pick, but then SSG fixed Red where it is on top again. I'm not an end gamer so I can't really answer your question except as I have answered it.
If you compare DPS with a champ, obviously champ is superior at the moment, but it's also ridiculously strong compared to every DPS class. If you compare red RK DPS with something similar, hunter, it's numbers aren't too far behind. You get a +5% incoming damage benefit, and DNF and much better aoe capability.
It's not the days of stacking 4-5 RKs like we used to in anvil, but a single RK DPS can have a spot in a raid.
As for heals, I believe blue RK is in a pretty good spot right now. I've successfully healed T5 AoD, Pughlak and HoR, and a T5 bloody threshold we did recently for ####s and giggles.
The healing positions in HoR can pretty much be done by any healing class, and healing slots in a full raid imo are a matter of preference.