I just wrote out something and it got x'ed out by the touch arcade app.
I am a long time gamer of cods. It has been the only game I ever play on console (like for real with Xbox live and stuff).
All call of duty games cost 60 dollars. plus live and the cost of the console. With modern combat 4, you will get 60 dollars (I even think a little more) out of mc4. It is such a well rounded game, real ADS (aim down sights), real live people with stable connections, AWESOME MAPS, like 7-8 game modes, campaign, leader boards, friends, and custom matches.
Plus with modern combat 4, the thread here on touch arcade will work you wonders. No one will chide you for asking noob questions, all of them there will always help. There are TONS of guns. Secondary sub machines guns to, something close to the automatic pistols we had in, (I can't remember it's either mw2, blops, or mw3) where we could akimbo the g13s and work people. It's got grenades that shot bullets, 4 different sets of available perks, there are 4 separate perks in each of the 4 categories. Snipers, shotguns, and assault rifles. 9 different kill streaks, you can have 3 at a time. And there is quite a good match of nubs to pros.
Dude what you shouldn't do, is say its to hard in the beginning and quite. This is my first mc4, and I ALOST quit. But I foot the charbtek and it changed everything! Trust me on this one, its worth 9x the price!