I know it's been out for a while now, but I only played it today.
It runs surprisingly smooth on my pc considering I heard it had high demands.
Like most RTS games, there are basicly 2 parts: the campaign and skirmishes.
MissionsI started off with the campaign which lets you fight as the Blood Raven space marines (no other campaign available as far as I know :P). They've mixed rts with a bit of rpg so that when you fight between missions you can upgrade your commander and your squads with equipment and with a sort of experience point system which lets you aquire certain traits. I really liked this system so far because it lets you really take control of the strengths of a squad and tune it to your way of gaming.
BossfightsThe missions (I think I'm in level 7 or 8 now) aren't too easy, but not too hard for a beginner either. After a couple of levels each mission ends with a bossfight. Sometimes the boss is a bit of a challenge and other times I find myself thinking, is dead already?..erm..oke.. You fight orks which are always plain funny if only for their acknowledgements and or screams when they run, the eldar (sometimes it's hard to see where they are standing, they're so thin) and after years and years of waiting..finally TYRANIDS! So far I've only played one mission against them, but they came in numbers as they should.
SkirmishAfter the first mission against the tyranids I wanted to play around with the tyranids myself (hey..I've played Tyranids on the table top for years now) and started up a skirmish. The units are quite cool, the abilities look awesome and it's cool to finally see them running around on screen. But (you probably felt this one coming, there's a but) the upgrade system is sometimes a bit vague because of a bit of a disorderly system of upgrading the tyranids. Next to that as a table top player I think I've got the right to whine a bit, they change the rules or application of some upgrades quite a bit (a tyrant with reinforced chitin or crushing claws is impossible in the book, rending claws plain useless in the book). But those are just small tears because gamewise its all good.
The real minus with the skirmishes is that there isn't much to do than built up fast, crush your enemy as fast as possible or hold back (a bit) to make the game last longer. Either way, because with at least the tyranids there isn't much of the normal rts base-building (just 2 upgrades to your main building) which makes the skirmishes boring quite fast. I don't see myself play skirmish after skirmish online, let alone against a pc AI. The last option is still tons of fun in many other RTS games. In some games (even in small skirmishes) skirmishes give you the time to get a feel for a side, but you kinda have to force yourself to do this in DoW2 otherwise you'll just built some basic troops, some large critters and stomp the opponent.
Conclusion:The campaign is cool. I like the tooling and upgrade system you use for your squads. The story isn't too deep, but name a rts where this ís the case... The abilities are quite cool, although there are always some abilities which won't be used in favour of cooler/stronger/better abilities. The effects of the abilities look really nice. But the amount of detail gets lost sometimes because either there is so much happening that you want to stay zoomed out or the detail is too small to really notice constantly. The acknowledgements are funny (orks), stern (marines) or arrogant/wise (eldar). But as cool as the campaign is, the skirmishes get boring quickly, and that's after playing only one skirmish. It seems skirmishes are just an obligatory option in this rts.
All in all:The DoW games (1 + adds & 2) are a must for the warhammer 40k table top gamer (if only to see the different armies move around digitally) and are fun for most other gamers. As for DoW2, have a go at the campaign and it might even be fun to play around extremely with the upgrading system to see how much it affects your game. Try a skirmish, but don't be too disappointed if you get bored.
For more info:
Dow2 website