This most is more in hope of salving some wounded pride than in expectation that you will want to read me blowing my own trumpet. Since my initial humiliations following my upgrade to the latest rev of COD4 I have played a few sessions and I am pleased to report that I am no longer the bottom of the table noobtard. Although most of the players are much further advanced than my humble 22 levels I seem to be able to make some impact and position myself around mid table in most of the games I play.
Partly this is due to choice of server. Many of the servers available advertise hardcore team based games. While these can be very enjoyable it is very difficult for a lone player to make an impact and you become easy pickings for any sort of co-ordinated opposition. I generally fare much better on free for all matches where it is every man for himself.
I am also getting smarter at choosing the right weapon for the map. My beloved M16 assault rifle is superb at medium to long distances in relatively open maps but cannot put lead in the air quickly enough to win run and gun battles in more confined spaces. The MP5 submachine gun has proven to be my saviour in these cases. The heavier so called "light" machine guns offer even more devastating killing potential but they restrict mobility too much for my liking.
I have played in a couple of very crowded free for all games with over 30 players. These games are complete mayhem but enjoyable if you are in the right mood. Running around with a submachine gun and grenades you can rack up a fearsome number of kills. Almost every where you look there is someone to hit. Camping, particularly spawn camping (players hiding near a spawn point to kill others as they spawn) is a nuisance but you quickly get to know the preferred hiding spots. A well placed grenade works wonders at flushing them out.
There are no penalties for dying so fast and furious killing on a crowded server is the quickest way to gain XP and advance. I still enjoy slower paced games however. Perhaps my favourite round to date was a free for all in hardcore mode with only four players on one of the urban maps (crossfire I think). We had no Hud and no minimap so we played a slow cat and mouse game tracking down enemies by sound.