While you say you can shoot down the choppers with missiles, you don't get a stinger till you hit level 30 (+/- 5 levels) so you are sitting duck for a while.
MW1 does have a more realistic feel to it, but you are left down to the attack of dodgy admins and bad vote kicks, so while dedicated servers mean you should always get better speeds, servers are always open to abuse.
MW2 does offer you more shiney upgrades, I like getting new call signs and badges, while it should not add anything to the game, it does keep me coming back for more. Yes there are cheats, but there are on all games, I used to find the worst cheats on MW1 were server admins, since no one could kick them.
Ultimately MW2 feels more like a console game (you can not lean), but I prefer it, but I did just reinstall MW1 as its nice to have the choice.
But MW1 is cheaper and does have a better single player game.