Why not try it for yourself as there is also a free weekend going on till 1pm Sunday?
That said I like it a lot, though in my opinion the campaign is not as good as DoW2 and Chaos Rising, though it does add a lot of RTS elements back into the singleplayer. Multi-player is quite fun, even though I suck at it. Last Stand is a pretty good laugh of course and you can transfer your progress from the previous games if you have them installed.
The DLC are somewhat of a hit and miss in my opinion.
The Race packs are really not worth it in my opinion, since they are only usable in the singleplayer. They also make the singleplayer laughable easy for most of it.
The skin packs are all really nice looking, though I think it really depends how big a 40k fan you are. You should also note that they are not usable in the Last Stand or Singleplayer, only in the main multiplayer section of the game. Personally I would say that the best one is Death Korps of Krieg, since it also has a rebreather sound added to all the voice clips. They are unfortunately not customisable though.
If you liked the Last Stand mode gamemode in Chaos Rising I would definitely recommend the Tau Commander. If you played a lot of it before than I would say perhaps go for the Wargear DLCs, I can't really fully recommend them since I have only tried a few of them. From personal experiences I got to say avoid the Lord General and the Chaos Scourer packs, they really don't do anything very useful as far as I have seen.