My thoughts on the game are that it's fantastic. This is the first big wargame I've gotten into since leaving the GW fold. The rules are simple but add lots of complexity to game play. The key to the game is the reaction mechanic that allows your opponent to reactic in your turn. This is a simple reaction of either attack or move out of the way but it can mess up the attackers plans big time. To counter this reaction you need to put suppression on the unit which is achieved through shooting at it. Some units are good at shooting at long range while most big damage occurs at close range. Close range is where reactions can occur, so this means you generally need a combined arms team of thinking, one unit to get the suppression down so another unit can get in close to mop up.
The game has another neat mechanic to avoid reaction in the command phase. The initiative is structured so that the smaller force (i.e. normally the one that has lost more units) has a better chance of gaining initiative each turn. Initiative lets you get more actions in your turn. You also have a command phase were you can perform actions without your opponent reacting but then lose the ability to react later in the turn.
Each turn presents a lot of options and difficulties in brining your plan together. The battle builder mechanic also allows each side to bid on scenarios in an attempt to make it easier for them to win or harder for their opponent. Battle builders can be swapped around to keep the games scenarios fresh (most expansions add a new builder as did the FFG tournament rules).
The miniature line associated with the game offers cheap but nice soldiers (though long barrel guns suffer a bit from the bend plastic) and fantastic wow pieces in all the walkers, aircraft, helicopters and tanks. Everyone always comes over from their games to check out those.
The rule books look fantastic. The rules take abour three readings to figure out how they all relate to each other and most of the rules are spread across the core book and several supplements (thankfully they do repeat the rules in each supplement that uses them so you don't have to get all of the books).
There are a few things that could be improved in the game. The main one is the shooting/armour combination. The shooting mechanic is taken from Dust Tactics where basically as the target gets tougher you roll less dice to hit. In Warfare the targetted unit then gets a chance to save equal to how tough it is. This means that some attacks are rolling 1 die to hit while the target gets 5 or more dice to save. The shooting rule works fine in Tactics where there is/was no save based on the unit type, but in Warfare the attacking dice either need to be higher or the same value across the board to work with the increasing saves.
For those that like realistic ranges you'll not like Dust Warfare which really crunches the range of shooting down to a little bit over the reaction range. I enjoy this though as you get a couple of turns of moving before getting stuck into the combat.
My complaints are minor quibbles and I really recommend playing the game. The main problem is the one whitphoto mentions; finding opponents. I have all the armies so I just need someone to play against but even that can be hard to organise. I had the game since pre-order days and in that time I've only really had two opponents who happily put aside their games to play this and neither has collected their own army.
Also for those turned off by Apes or Zombies you don't have to use those units. There are plenty of different build types available for each army (and each faction plays distincitevly enough from the others).