I'll break it down:
-The exo-suit super jumping and boosting around is fantastic and makes the gameplay seem more fresh than the average CoD game. It changed the dynamic of the average player movement around maps in multiplayer in really good and fun ways.
-Most of the multiplayer maps are really good. They are much smaller than the ones in Ghosts but they are not shitty three-lane like Black Ops 2. And with the exo-suit you can now jump around a lot of roofs now instead of just sprinting everywhere.
-There doesn't seem to be any particular setup that is "overpowered". They nerfed panic knifing, you will not die by melee unless you are literally touching your enemy. Noobtubes are useless even with Danger Close. Quickscoping is back and it's kind of annoying but not nearly as annoying as previous games, especially since you are a much more difficult target when you can jump and boost around. Also I don't think there is any quickdraw for snipers which is good.
-Flak Jacket is actually useful.
-Killstreaks are powerful but much more difficult to earn and the really high ones don't last long at all, maybe like 45 seconds if even that. Just a UAV requires like six kills in most gametypes now. So basically you're not gonna get spawn-raped frequently. Also killstreaks are customizable, or you can remove them to have more perks and equipment, or have two primary weapons or whatever. There's a lot of different classes you can make.
-There's no more bullshit about prestiging requiring 300+ squad points like there was in Ghosts, you get to 50, fill the bar and prestige. Simple.
-No more support streaks so you won't have scrubs getting juggernauts and oracles and shit.
-Guns actually have recoil now and don't kill in 2-4 bullets, so it's possible to kill someone even if they shoot you first. It's not really challenging but there is much more of a learning curve than previous games in the series.
-Even though the maps are good, they don't seem very well-optimized for the new exo-suit. For some reason it seems like they didn't take into account the new movement styles when making the new maps, so moving can be awkward sometimes (for example lots of rooms that are too small to effectively use your jumps/boosts).
-Most of the perks are just rehashes of previous games, same with attachments and grenades. Also the custom exo abilities (invisibility, shield, etc.) are pretty much all useless (the good thing is you don't have to use them at all).
-The graphics and game engine haven't been significantly improved at all since Ghosts.
-A lot of the guns just plain suck. I found myself sticking to a couple SMGs and assault rifles for my first 50 levels (I just got to 1st prestige). Because of everyone being able to go sonic speed all over the place, using LMGs is pretty much pointless, and the three shotguns available are AWFUL, they have shit damage and shit range. Also the new riot shield feels like a piece of cardboard and the secondary pistols are borderline useless, I mean it's not like I expect them to be amazing but even as secondaries they're pretty bad.
I have about 15 hours played in multiplayer now, and I think what it basically boils down to is, if you like Call Of Duty games (especially the Black Ops ones) you will like this, if you don't then don't bother with it because it's *mostly* more of the same.
Personally I really enjoy it though.