TBH i'm not aware of any major hack issues on Xbox. It's certainly not rife.
The easy hacks, wall hacks (i.e. jumping into the roof on Metro, near US spawn) are mostly useless as you can't obtain many kills whilst using them. Glitching inside of walls by constantly killing/reviving squadmates into the corner of a room means you just get stuck; you cant shoot out, IIRC the walls are double-skinned.
Out of the 400+hrs I've played, I only recall 2 instances where I believe I was killed by hackers, both on Caspian border.
- Trail a guy in a straight line only for him to magically appear behind me and shoot me in the back.
- Trailed another guy for ages by the woods (B on conquest) only for him to spin 180 degrees and kill me with 1 shot. I had full health!
ok guys came across some blatant cheating tonight, running towards a guy he sees me and low and behold suddenly i lag out and hes behind me and im dead. 2nd one this guy running in front of me and i have him bang to rights as soon as he takes the 1st hit i start lagging again and then being only yards from him the screen freezes for a second and again im dead, the 2nd one it happened with the same guy 3 times and at no other point in the game did i experience lag except when trying to kill these guys. any thoughts?
on pc you used to be come across guys using lag switches all the time. btw im not sh1te either and i had these guys bang on firing 1st everytime 
Regards lagging out and enemies getting the upper hand, it's worth bearing in mind that (I think) hit detection is calculated player side, not server side. If you have a laggy connection (i.e. connecting to a US server) you will die lots! Enemies will appear to kill you with far fewer bullets. Also bullets will appear to be able to follow you around cover
http://www.youtube.com/watch?v=ZzzeUlizMxYThis explains why I can raid a room with the USAS or DAO12, spam enemies in the face point blank with 3 or 4 shots only to die without even hurting them.
