Are people cheating?

So I've been playing allot of Uncharted 2 online and I've noticed some really unusually quick kills from the other side of players. Something doesn't make sense to me, I'll be there firing loads of bullets in their face and I'll get the kill eventually, but sometimes they'll kill me within a couple bullets, it just doesn't seem right to me. I know for a fact I have some really good rounds, sometimes clocking in 18-23 kills per match then all of a sudden I have a really poor round with a load of new people and only get 5 to 10 kills, so this got me scratching my head. Some of these people are very good too, too good to be true.

I've seen some video's on youtube of people deleting the updates and modding some game saves with hacks etc, so I guess there's that loophole for people to cheat. Also seen all those Lag Maker mods and such for Xbox live, so its not impossible.

This stuff really pisses me off since I only enjoy a few online rounds on some multiplayer for an hour a day and now that funs gone out the window with these cheats.

Anyone else feel like this with the online scene?

There is a way to "glide" lag switch that someone did a video of, which is rare, but the answer is usually no. Its purely based on region and lag I notice. I've had times where I empty clip into someones head and they live, then times where like I barely get tagged and I die. I really don't get it either, but I'm certain its lag. Especially since UC2 has a really stupid locked selection. Like, you can be in the USA, playing people in europe and japan, so the variance gets really dumb. Only play this shit at reasonable hours during the day if you want a serious match. I don't take it to seriously, as recently patches have been pretty solid.