What mods get you, what mods don't get you...

Mods get you options. Planes that were before unflyable are now flyable. Gunner positions that weren't usable are now usable. Maps are made with details to realsim, especially by tater. Check out the maps in works at AGW forum at http://agw.bombs-away.net/showthread.php?t=70472 for some amazing historical maps. One of the things you DON'T get are changes in flight models. I think the idea that fms are changed is what keeps many from trying mods. They have to realize that their little Yak is gonna perform the same in the AAA arena as it will anywhere else. The "new" planes, actually existing planes that have been given cockpits and gunner/bomber station, use the existing flight models that are already in the game. This beefs up the flyable planes. This adds about 55 more to fly, including great ones like the B-29 or the Catalina.
Amazingly, the modders also created an option for yu, to fly IL-2 without your installed mods, if you so choose. They have program that lets you pick between modded and not modded, and also between 4.08 and 4.09beta. Mods are easilt downloaded at the AAA forum site, seen in my links.