What people seem to get wrong is that the use of the Essence Engine in Dawn of War II makes it Company of Heroes set in the Warhammer 40k universe. This is simply not true.
Dawn of War II is really different from Company of Heroes, but so it is from Dawn of War I. And this is what must be perfectly clear to everybody who played Dawn of War I and want to dive into Dawn of War II.
So what's different? First of all, the number of units in the roster and on the field was strongly reduced.
For example, a Tactical Space Marine squad is one of the 8 Space Marine unit types, comes with three members and may be equipped with a Sergeant after reaching Tier 2, which makes a total of 4.
Orks on the other hand have Slugga Boyz squads of five (again plus a Nob after Tier 2) and are much cheaper, which makes it roughly 4 Marines vs. 12 Orcs.
Now, the point is that this is actually a really good gameplay decision: You need to care about your units, because the death of a single Space Marine has a much greater impact than it had in DoW I, since you had 8 Marines and could reinforce in the field instead of having to retreat to your base (another change in DoW II).
Apart from that, Space Marines are finally what they ought to be: super warriors. You buy them for a lot of ressources and they are really tough, but you must take care not to lose them.
The new standard mode is 3vs3 and maps are much smaller. There are Requisition Points, Victory Points and Power Points on the map. Instead of building generators in your base, you capture a Power Point and pay Requisition to upgrade it with power plants.
Before the game, each player must choose one of the three heroes per race. This hero will be available troughout the match and may not really die, but is incapaciated as soon as his health hits 0. Now the player must either pay Requisition to make him respawn at the base (the longer you wait the less Requisition you have to pay) or a teamate's hero comes along to help him up.
The heroes are very stong units and have special abilities that clearly sets them apart from each other: The Force Commander is strong in close combat, can equip a thunderhammer or a power fist, or get terminator armour, while the Apothecary can heal himself and teamates in the field.
All units gather experience and get stats boost as they rank up in levels.
Games are really fast, because you need not build up your base, but dive directly into combat. Requisition rate may be rather slow, but this is what the game is all about: If you keep your units and retreat them in time, you have to pay about half the cost to reinforce them, compared to rebuilding the squad from scratch AND you're going to keep the squad's experience. The other guys reviewing the beta of this game seem not to have realized that after 4-6 hours of playing.
Since you alway have a rather small amount of forces, you must make clever decisions in order to hold most strategic points on the map. If you blob your forces, the opponent may travel around the map and decap your points, if you divide them up, your opponent may hit unsupported forces with a superior army!
There are a lot of other things new to Dawn of War: Suppression fire, reworked unit abilities (like infiltration), knockback, and great implementation of jumping for assault troops. Every unit on the field is easy to kill if the right counter is at hand. So the rule is combination.
If you have any expectations this game to be like DoW I, you will fail. If you want to see CoH in it, you will succeed. This is what drives a lot of people away. Instead, free your mind and enjoy the game as it is: Different!
And last but not least: There are still some issues with gameplay, NAT negotiation (I am not big fan of Games for Windows Live either, but it has some good features, too), game crashes etc. But this is a beta and this is what betas are for. I am pretty sure, Relic will handle all this. The game is great overall, but it does not quite reach it's potential. On the other hand, there are lots of possibilities to improve that.
We will see how that works out. I'm really eager to see customized armies fighting each other in fast, small scale battles in the fields, once the game is out and the army painter is free to use. This is sure going to be fun, and Relic has since I know them done a really good job to do all they can do to improve game experience, and I am quite confident, they will manage Dawn of War II also.