I spent a lot of time with IL-2, because I saw some good aspects and
 great potential within the game. It was definately no 'junk'. 
 I tried many different combinations in joy stick calibration before  the 
 game.  .... deadband, filtering and scaling you name it. 
The filtering is  the  main reason behind the super twitchy roll
 responses. It messes up the response time of "no aileron input"
 status. Thus, even after you centered the stick after a certain bank
 angle, the system doesn't recognize it.
 Another thing is, rudder response is also super twitchy. I use a MS 
 Precision Pro (older version) Stick. The rudder function is implemented
 by the 'twisty stick base'. Even a slightest touch of the base sets my 
 rudder input to max. I had to practically dampen, smother, and kill this
 response by fiddling with the scale, filter and deadband. 
 After this painstaking process was through(I think I recalibrated my
 stick about 20 times), my feel on the planes weren't much different 
 from AH like others have said before me. I don't seem to feel any sort
 of strange, or unfamiliar responses. Of course overall, it isn't as crisp
 clear as AH, but it wasn't too wierd either. A little less predictable than
 AH, that was all. 
 The overall problem I've noticed with IL-2, the 
REAL problem behind 
 the trickiness in handling, is the fact that some planes accelerate just
 too fast, and other planes(LW planes 

 ) accelerate like a slug.  
 I've heard of a phenomenon where a plane's initial acceleration rate 
 is determined by how fast you are going. Which means the slower you
 are the lower your accel. rate, the faster you are the higher your accel.
 rate. In some planes, this phenomenon is just too extreme. Perfectly 
 trimmed, careful control.. you can barely accelerate it up to 400kph 
 in level flight. Give it a slow dive, finally speed up to about 500~600
 kph, the usual speed we would fight in AH... make one move, the speed
 drops to bottom and doesn't come back up. Overheat that damn engine
 and it would still recover only about 70% of the speed before. 
 Thus, in IL-2, we usually fly and fight in about 150~250 mph speed
 area. Imagine we fly and fight in 109s at 150~250mph in the AH MA.  
 These sort of goofy accelerations make it almost impossible to enjoy 
 flying, fighting in a plane that responds crisp and well.(IL-2 FM isn't
 that bad if you fly planes that hold constant high speeds...)  
 There is a possibility that AH, with everyone running their engine at
 max pitch max throttle constantly may be a bit too crisp. Too easy to 
 handle planes. But in the case of IL-2, the engine power and acceleration
 factor is just too extreme. 
 ..
 ps) Thus, in Multiplayer games, people exclusively fly so called 'ubers'
 , especially La-5FNs, which compared to AH La-5FNs, seem to hold
 low speed sustained turn awfully good. (feels like spitfires, the damn 
 basta*ds) 
 ps2) conclusions: flying IL-2 multiplayer with plane limit(~1942) is really
 fun, since everybody has trouble maintaining there planes to do 
 something. Playing most other FFA games just plain suck.