Hamish this is a good point. Doom3 is just pretty ultra realistic, as is America's Army Online.. although the id soft game really suffers due to lag (though update 1.3 has REALLY improved it, I get a respectable 80-120ms now), so it should be interesting to see how well ET:QW and Q4 fair next year.
But AAO certainly isn't exactly chart-toppingly popular. I'm begining to believe it's the balance between realism, and fun.
The weapons for example really don't have that different attributes.
Pistols, Sub-Machinegun, Machinegun, Rifle, Sniper, and Shotgun are each of the types of weapon; the only difference in power between the individual weapons in the classes are between Counter-Terrorist and Terrorist specific weapons.
CT are generally lower powered, but more accurate, and silenced.
T are more raw power.
The weapons they both own however are the same power in each of the class. More Expensive != More Powerful, but you can buy your favourite real-world weapon.
I'm still unsure to if the choice itself makes people enjoy the game more, but I know that the actual purchase system seems to annoy quite a few people. Especially given the better the opposing team, the hard it becomes for your team to win if they keep winning because they can afford the better weaponry while you could be stuck with pistols.
I guess to a degree this does show the tactical element involved, and the fact that you have to wait out a round .. does mean you tend not to just rush in all guns blazing.
The level designs seem to play a big factor too.
I've found that the most popular gameplay types out of the four available are Defuse and Hostage. Moreover Defuse is used far more, with de_dust2 being the most popular map.
What is interesting about the maps is they're not design to be equal, or fair.
In all, the problem I've been having trying to figure out what exactly makes it great is the fact that it isn't one thing for one person.
It's the fact it actually has small things that appeals to many types of people.
