Increasingly fun gameplay. You have access to 9 factions, each with their own unique capabilities. The campaign will take hours to finish, due to its open-ended nature. There aren't many cutscenes to the game, and some aren't done right. The Space Marine and Chaos campaigns have *cough* well done cutscenes. The campaigns aren't true to the backstory of the Warhammer 40k universe, with a good reason.
Multiplayer is equally hard, as you are often pit against people with a higher skill level than you. You will come across some new players looking to learn things. Small tip, keep your rank at a good level and you won't be kicked. Or that's what happens to me. Another good tip is to make good use of your time. Its a matter of minutes to get you that Baneblade, and the fate of your scout marines depends on good timing, and always get these control points.
Mods are cherries and Soulstorm is a cake. Sadly, the mods usually don't work together, so you're better luck trying these bigger mods.
"Bigger" mods are mods such as Titanium Wars and Ultimate Apocalypse. These mods add many new features to the game, and are a must-try. Sadly these mods don't have players playing multiplayer.
As a "classic" there are a handful of players, so refreshing your server browser is a must. Graphics are dated, since the game uses the first Dawn of War's engine. This game should run fast on an average PC, and only mods can really slow this game down to a stutter.
A well-made RTS in my opinion, and a good for frustrating youself.