Ah... relief from working... I can write a quick summary of my own...
Base Building
There are two kinds of structures in CH: base structures and field defences.
Base structures include your usual RTS production buildings, including the various barracks and tank depots. There doesn't seem to be any good reason to produce more than one of these in the games I've been playing. These structures can only be built within range of your main HQ.
Field defences, however, can be built anywhere in your territory (I'll come back to territory below). Field defences include MG Nests, mines, barbed wire, sand bags and so on.
There's one additional thing you can do with base construction which is to set your troops up in a building in the field, in territory under your control, and convert it into a barracks. This is a pretty nifty way of producing troops at the front line, but you won't get any tanks there. If the enemy captures that piece of territory, however, then they prevent you using your barracks. Oh, and if that building is destroyed then the barracks is destroyed too.
Territory
In Dawn of War you captured strategic points to up your rate of resource gathering. Same deal in CH, but the points give you one of three resources: manpower, munitions or fuel. You need a lot of manpower, some munitions and a bit of fuel (more fuel if you want lots of tanks). Resources don't run out, so you're just affecting the rate of accrual of resources by having more of these points.
As you get more troops, the rate of accrual drops, meaning that you can't boom so easily... a large army is hard to maintain so you get less resources coming back to you to spend.
Each point is surrounded by a territory. If you control the territory you can build field defences in it. Those defences stay there even if you lose the territory, until the enemy destroy them (or use them against you, in the case of sandbags.
In the skirmishes there are also some key points that you can capture in a very BF style... capture over half these points and your enemy's tickets count down... when your enemy reaches zero tickets, you win. However, these key points aren't strategic points themselves, so they're additional things to capture.
Squads and Experience
Squads are cohesive elements, which is a feature I love. I hated needing to build X number of guys and throw them as a mob at some defences. Have X-1 and you lose, have X and win... so CH does this well by pitching variable size squads according to their role: 3 engineers, 6 riflemen or paras, etc.
Over time, squads gain experience. Experienced squads fight better.
Of course, members of the squad die, but if you pull them back and reinforce them then you get to keep the squad's experience. This can be a real reason to pull back from a position to keep a decent squad, knowing you'll counter-attack in a few minutes. Helps keep the battle rolling back and forth, and sometimes gives a reason to chase down an experience enemy who is crippled, rather than just holding to your defences.
Cover
Cover is a key feature of the game. There is soft and hard cover, each offering differing levels of protection. A shallow ditch and a wooden wall provide soft cover, a stone wall or sandbags provide hard cover. An MG behind hard cover is a tricky thing to assault. There's also buildings, some of which you can station men in. An MG in a building is a fearsome enemy and I've used this to hold a bridge sometimes indefinitely (of course, they can always sneak around the sides...).
There's a neat feature where it shows you where your men are going to be placed, very roughly, when you point them near cover. Also, when they're getting hammered they'll seek cover nearby... that said, it's usually too late by that point.
Vehicles
Vehicles are immune to small arms fire, pretty much. MGs can hurt the half track a bit, but you really need AT weapons. You can research some basic AT weaponry for your troopers, but nothing hurts a tank like a well placed AT Gun to shoot it in the arse.
However, vehicles can't capture points (except if you're a tank commander, where you can get
light vehicles to capture points after a while).
This can allow you to roll a tank forward to mow down the enemy while you get your troops to do this and that around the edges. However, it's also my experience that a lone tank tends to get mobbed.
Commander Types
This one is a new one for me: commander types. Your commander gets experience through a map and this experience he can spend in one of three trees: infantry, airborne or armour. Infantry get the defences, artillery strikes and so on. Airborne get paratroopers, airstrikes and some other useful airdrops. Armour get the heavy hitting tanks but is a slow tree to develop.
There's not a lot in those trees, but they are versatile and multi-use. I play a lot with airborne because I like mobility and appreciate the ability to have almost lost a point and yet be able to throw paras in there to take it back.
This means you can be playing with largely similar troops, but because you've chosen a different commander type you end up tilting your fighting in different ways.
... and that's all I can think of on a first pass.
Hope that helps.