Rather than repeat what dozens of reviews have already said by trying to be comprehensive, here are some things about Homefront that many reviews have missed.
The maps aren't just big. They're square. By that I mean merely that they're not alleys like Bad Company 2's maps, with each team coming from a definite direction. In Homefront, you can almost always be attacked from any direction. There are battles where the map is evenly split between factions, but matches more often involve a scattering of players... leading to more dynamic gameplay.
Are snipers bothering you? Send out a scout drone to reveal his hiding spot to your entire team. If you're playing Ground Control with 32 players, it's often possible to sneak around and simply shoot that sniper in the back of the head.
I generally enjoy Homefront multiplayer, but I'm usually among the top players of a match and I realize that skews my view. So here's what I think multiplayer is like for lower-scoring players... and how the game helps such players.
You have probably heard of the Battle Commander system which makes it more difficult for skilled players to keep killstreaks going (Battle Commander is a game mode — you can join matches without it). What's less often touted is the availability of 500 Battle Points to each player at the beginning of every match. That's enough points to buy a drone, a rocket launcher, or a flack jacket.
Does your aim suck? Buy a rocket launcher. There are few things more satisfying than using a launcher to blow up someone's helicopter or tank (tanks require multiple hits). You start off with EMP grenades, so you can often "stun" vehicles long enough to aim your rocket carefully. If someone blows up a tank after you EMPed it, you get points for that.
Or you can find yourself a nice bush to hide in while you guide a Wolverine battle drone. By level 6, you can also guide a scout drone and earn Battle Points by marking enemies for your teammates. By level 10, you can hop in a Humvee and run people over; or park it and press Y to quickly switch seats and mow someone down with the turret, if a buddy's not there to shoot for you.
Even if you're out of Battle Points, you have the choice of spawning directly into an allied vehicle if somebody else bought one. Riding shotgun in a chopper or tank is lots of fun.
I'm not going to lie to you. Sometimes, Homefront multiplayer feels unfair. The Battle Point system means that momentum matters. Occasionally, a match ends with one team utterly dominating with multiple attack choppers and/or tanks. That can make it difficult to remain alive long enough even to see what's shooting you. There are also snipers who watch spawning points, but I've never seen them able to do this for long.
Homefront multiplayer gets my blood boiling at times. I generally enjoy it, though. I would describe the pace and feel as a happy medium between Modern Warfare and Bad Company 2…with more vehicles, more open maps and a flexible skill mod system.
As for the singleplayer campaign, all I will say is that it is short, but probably not much shorter than a Modern Warfare campaign if you removed all the times you had to respawn because of the greater difficulty. Unlike others, I didn't buy Homefront for a John Milius story. I bought it to shoot stuff.