I love the lights of the warp mods, available from here: http://dawnofwar.filefront.com/file/...the_Warp;81448
The mod adds a lot of cool stuff to chaos, like kharn the betrayer, chaos lieutenant, terminators.
Guard get the tank variations, like vanquishers, demolishers and exterminators, upgrades for them like pintle mounted heavy stubbers, melta guns for guard squads, the shadowsword titanicus (baneblade variant) hydras, conscript squads (guardsmen with lower stats, coming in squads of 30) and the ability to deep strike in troops by valkyrie!
Marines also get bikers, venerable dreadnoughts, command squad, devastators (equipped with plasma cannons, lascannons, missile launchers, heavy bolters)
The models are all new, and there are no stand ins, plus it changes the squad and vehichle cap to 200.