I have had exactly the same issues and also purchased the full pack to have some other aircrft to fly out in the “real world”.
The Vodochody is uncontrollable and I cant work out how to keep it stable or on most instances get it above 250ft from a take off. However, I love flying it in a race and it handles totally differently in these to how it handles in the rest of the sim.
For the F-51, I can’t seem to even get off the ground! No amount of left pedal/gentle increase of throttle stops it from veering off to the right.
The AT -6A is a dream to fly, well balanced and great for island hopping I have found.
The SNJ-4 requires a huge amount of fiddling with the rudder trim that makes it tricky to handle. I get it has a lot or torque, and tring to find a balance to keep it on the straight and level is tricky.
There is some work to do on the flight models of the aircraft ouotside of the races, and I wish I had gone for the cheaper option than the £49 ($60) full package as, unless I am missing a big chunk of the races package, other than the liveries and aircraft I cant seem to see a big difference for the additonal spend.
If you were to purchase a stand alone “racing sim” on a PC or other platform I believe you would expect to get a lot more for you spend than what has been delivered here. I know this could be considered as comparing oranges with lemons, but if you were to consider the Reno racing pack as a stand alone product, (it has the price of one) it doesn’t have much depth that I can see. Or maybe I am missing something.
I do enjoy and find it thrilling flying around in circles in different aircraft and trying to comprehend how some other racers have completed their races/times trials minutes under those that I have achieved, but I envisage this wearuing thin after a while.