I really liked it but the UNSC seem a bit overpowered against the Covenant. It feels like Spartans are more powerful than the Honour Guard Elites because of their shield, and from what I can tell from playing skirmish, supplies are gathered quicker by the UNSC than the Covenant as well. But then again the Covenant do have the energy shield for their base and the Scarab, which can pretty much murder any unit it comes across.
I've never been a massive RTS fan. I've played through Starcraft and the Brood War expansion, and I played enough of C&C for it to get boring. The controls work surprisingly well for a console RTS as well. Halo Wars is worth at least a rent if you're looking to get into RTS games.