I patched MW3. What else would I have done for several days?

And seriously: Go back and play all of the games. MW2:Mercs has no chance at all against any newer incarnation of Mechwarrior. The few things I remember at the moment: Bugs, a good amount of them. Shots are delayed by half a second, it feels terrible. The AI is as stupid as possible - it doesn't shoot much, it can't maneuver. The worst thing, however, are the messed up hit-boxes: In the whole game I was able to kill about five enemies without shooting both of their arms off first - if shots even got registered. These arms had the strangest hit-boxes ever. Once I did an alphastrike right towards the head of a non-moving Atlas and both of its arms fell off (using a mixture of SRM6 and MBL on my medium 'Mech). Placing weapons in these arms was a complete waste, since they were about the only places ever hit by enemy fire*. The last thing that comes to my mind is the 'Mechlab. Maybe it is faithful to Battletech (I don't know), but it certainly breaks the game. 14 MBL? No problem. A UAC20 with only 5 rapidly firing shots? Check.
Don't get me wrong: The game probably was great for its time. I really liked the "Mercenaries"-aspect, like I did with MW4:Mercs. I really liked the story, it actually was understandable - completely unlike the MW2-story. Also, I played MW2 back then. And I loved it, although it suffers from mostly the same problems.
The games after MW2 were built upon gained experience, at least that is what it feels like. MW3 seems to get better and MW4:Mercs definitely is by far the best of all of them (I first played it three years ago). I know a couple of games I played as a child, games I still play every now and then - despite some of them being awful. But after an unbiased look...MW2s glory must have worn off about a decade ago.
It is still a fun(ny) experience, though.
*Maybe the strange hit-detection was caused by MechVM? I wouldn't know.
Ah, one more thing: How can MW2:Mercs be the best Mechwarrior game? How the heck? If I was admin here, I would immediately kick you. Ban you from the Internet, actually! Maybe a little bit of torture would be appropriate, too.