Definitely a stray from traditional RTS games. It's a little repetitive, but makes up for it in many ways.
The graphics are awesome, especially for it's moderately low cost to your machine. The environment is detailed, and you can come across some pretty well done weather throughout the campaign. In combat, various explosive, plasma, and other flashy effects give you that satisfied feeling as your orbital bombardment annihilates an army of orks.
The single-player campaign doesn't have a stellar, unforgettable storyline, but it's still on the better side. The single-player missions, unfortunately, are kind of repetitive - you're either protecting an asset, destroying a base, or killing a boss. Unlike games like Starcraft 2, where advanced base building capabilities allows you to have a variety of missions, Dawn of War II is restricted by it's squad combat system - you really can't do much more than drop the player off and tell them to blow stuff up.
Don't let that discourage you, though. Even though the missions are repetitive, they don't get boring very fast - whether you're jet-packing into a group of annoying Eldar, razing down troops of orks with an ultra-speed machine gun burst, or charging your Force Commander through a swarm of tyranids, you always get that satisfied "Owned, motha f*ka" feeling, which is always a plus.
In the end, it isn't a game you should get for it's stellar storyline or varied missions. But if you like tactical battles, diverse combat techniques, fun multiplayer, and seeing stuff blow up time after time after time, this is worth every cent you'll pay.