Here. In summary:
Gears multiplayer wasn't broken, so in that aspect they haven't fixed it. But neither have they thrown the baby out with the bathwater. The experience is tighter, sharper and more concentrated. But also very familiar. But that's the thing - innovate too much and you can spoil the experience. But don't innovate enough and fans looking for new thrills will feel disappointed and short changed. The best barometer is sitting back and watching the rest of the party playing. And Epic can breathe a sigh of relief. This works. From expressions of pained concentration, through constipation face, vinegar face to whooping like a lottery-winning macau monkey, no geek left unsatisfied.
A lot more of that through the link.