So I've been playing GoW: Ascension multiplayer extensively, and I must say it's very enjoyable haven't even touched the single player yet. First off multiplayer doesn't feel tacked on, you can tell Santa Monica put some thought into it. It runs smooth, even while all 8 players are on screen, no technical issues or slow down whatsoever. And one of the bigger positives is how quickly you are able to get into a match, it's in-between the speed of KZ 3 and U3.
As for the combat in multiplayer it is very satisfying especially when you land a brutal kill on an opponent. Level design is very well executed, there is traps all over that you can utilize to wrack up your kill count or death count. The difficulty can also be brutal, at times you can get away with just pressing Square and getting a kill maybe two but eventually you'll find a player that tears you apart. My biggest issue is on the two games types I've played Capture the flag and team deathmatch there is only a total of 4 maps which I just had hoped there were more.
So that's my take on it, I feel multiplayer is well done and it feels refreshing and unique.