well, i played sp 2 times, and now i am lvl22 in mp.
my feedback:


suit:
-sp
well, like c2, only that mobility isnt using suit energy, you can almost run endless, which i think that isnt the best idea.

-mp
i think armour is too weak, and there can be arguments, for and against that you move in stealth slower. but for moving slow, the energy also could be hold on more.

-module
like in c2, there are different between sp and mp. in sp, you can choose 4, which are categorized in a way i cant explain and i dont like these kind, in mp you can choose 3, but this time, you can choose how you want to mix.
what i think, cause armour is to weak, armour transfer 1-3 is a bit useless. anyway i think 15/25/35% would be fine.
i didnt tried all modules, but i am missing nano-recharge. if i see that right, armour enhance is in its sense already included like the airstomp. prety all modules are like in c2, just with other names. auto armour , although i dont use it at the moment, its ok, it does its sense.
let me call it mobility enhance, i think, that could be also included, but faster running, or bring something back from c2. if the player wouldnt able to run endless, then the module like in c2 would be harm perfect.
-weapons
in sp, i could get fine with that. only, i think extenden magazine for scar (didint use scarab in sp) with 80 ammo is exaggerated. in mp, aiming is really damned. the aiming in c2 was veryyyyyyyyyyyyyyy better. i think fy71 itself with the actual handling/aiming, is fair, but in compare to other weapons, then its still op. i dont like the unlock system, where you cant choose your next unlock, but i see the sense in it, that u try first the attechments before you get your dream weapon.
dsg need now 3 shots, but now its fire rate is like you have rapid-fire in c2. yeah, i think its ok, a bit more competiton, and a more chance against toxij:D::D
gameplay:
the story is a class for its own. well, since yesterday i have c3, i played the game finish 2 times, and now i am lvl22. so in my case too short. yes, you have more feedom to your way. i wished, you could take more ammoreserve for assault rifles, because the aliens want much ammo. with scar and dsg, you get out of ammo too fast. i think its ok that you need much ammo for aliens.

mp:
-maps. well, at the moment, a question of be used, but what i liked the new skyline. and generally, there are definataly good maps.
-great, that you just click a player, and get options what you want (friend request,votekick...)
-i wish ability to save filter-options. anyways, i cant get why ppl have over 150 pings, why they dont filter to a low-ping server...

the onlyst things i found is, that there are few cornes, where you cant catch if u jump to it. generally too all corners, you should able to catch the corners.
i often think i hang in sp, if i want reload, run, aim, something while i want do more things at once.

thats all what i had to say, that was my feedback, hope i could give a usefull post.