Good and bad of those games...
Dawn of War has a general imbalance of allowing the AI to have more than one army against you, including duplicate commanders. Not a big issue in itself, but without true line of sight and depending on the species matched up, it becomes difficult to hold a front against opponents.
Beyond that, the campaign is actually well set up and gives you a variety of puzzles which require both tactical intelligence and conservative use of your men. The original can be lotsa blowing shit up fun.
My advice: Buy, but not expecting anything better than Starcraft style gameplay.
Dark Crusade has the down side of introducing the Necrons. Even their most basic units have the ability to become more powerful than medium-high units of other groups. Furthermore, their commanders are overpowered AND they have the potential to have more than one because of the imbalance mentioned above. So it can become amazingly tedious to fight them. (If I am correct, the Necrons in teh table top all shut down after losing a certain percentage of their forces. Here, not the case, but they still have the individually overpowering attributes)
The good is that the open campaign map gives you a variety of objectives which you can take in any order you wish. As close to Total War as they get. The maps are fun with multiple angles of approach, catering to every species. The Tau are pretty fun, but also have plenty of weakness to counterbalance them. A fun buy now that it's cheap.
My advice: Buy, but be patient in the face of Necrons and be willing to poke around online for solutions to one or two challenging maps that leave particular factions at a disadvantage.
Soulstorm has the major downside of a linear style map, leaving you to largely fight whichever one or two factions dominate. Unlike Dark Crusade, whatever you build in an area is not preserved, so every time you attack or defend, you have to start with a single command center and work up. Especially when a player is making constant counter-attacks, it wears out the fun of a given map. The Sisterhood is fairly cool, but they really boil down to a very short range version of the Space Marines (whodathunkit).
The good? Well, you have two new people to play with. But the Dark Eldar and the Sisterhood tend to remind me of other groups (guess which). If the Tyrannids were here, they would compensate for both.
My advice: Unless you're getting it for pennies on the dollar and are fine with skirmishes only, it's a pass. New units don't add that much and the campaign is bleeding painful.
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