Playing HotW or NV it's still a pretty trying spec even though they are significantly easier than DoC to 'master'. There's still a lot of similarities in the play styles which makes them tougher than other specs and classes, imo. Timing dots, CDs, energy management dependent on the fight, Symbiosis - the list goes on.
The biggest decision you have to make if you want to play feral is how involved do you actually want to be with the spec. If you want to play to a pretty decent level and maybe a bit above, HotW and NV will suffice perfectly but if you really want to push your own ability then DoC (at least how it stands right now) is what makes this spec the best in the game right now. If you take the time to really get the hang of it I'd be very surprised if you didn't absolutely love it and I think you'd be surprised how much it makes your game play improve.