Got the chance to try this flight model, and I find it absolutely superb. Piloting the MiG-21 is my favourite part, as high-alpha makes crazy loopings impossible without significant thrust, and makes landings feel realistic with wind. It's like flying a real airplane with a 1990s filter!
Though I'm not a hardcore flight sim player, I've played the old WWII Jane's, MS FS 2000, and Wings over Israel, some Novalogic sims, and H.A.W.X. (all with the keyboard in the past -- wow). Overall, your flight model compares favourably to all the above. I'd even say I like it best compared to my favourite, Wings over Israel, because in that one, the high alpha stalled dramatically. Congratulations on such a good job.
I know this is a dev nightmare, but maybe you can consider including a code switch between easy/unrealistic flight mode (no wind, less stall, etc.) and the complete model, if it turns out to be a problem for people to play?
Part of the fun of playing the sim with a more accurate model is the extra challenge. Right now it plays well with a joystick, and gives a feeling of satisfaction that you've turned and landed successfully. The enemy jets are quite close, so if you just gun the afterburner you're fighting in about a minute, but of course, it's no arcade.
I think you prefer the challenges of the realistic flight model. In the end, your interests are what keep this project alive, so it should please you so you remain motivated.
On a side note, the lack of a HUD makes it difficult to read the values. I almost want to code one for you.