I just love threads where people brag about their skills. Then, after the initial flaming, random new users will come to the OP's defense, whether he is a clanmate or friend or the same person.
Let's get this straight: You're a 3-star general. Congratulations on the hard work, but realize that someone will ALWAYS call you a nub. Someone will always challenge the size of your e-pen0r (just look at how many "I OWNED LORD#OF#WEED LOAZ I IZ LEET" threads there are). The best you can do is take the annoyance in stride. The point is, you've devoted more time and effort into the game than they have (or maybe you haven't), and as a result, have a higher rank than they do. In all honesty, I could come to respect a general with a KDR below 1. It just shows to me that they have the dedication and persistence to play through a game.
The point is, just play the game. Don't be a prick and challenge people to match their e-penis with yours. Just play it the way you want to (if it is with a G36E, so be it) and take the insults in stride. If anything, being called a nub when you are clearly better is a compliment.