Hi again
Actualy, I would do the other way around if you already have Lock On. I found Black Shark performing slightly better than Flaming Cliffs. It seems the engine got at least some more refinement from Flaming Cliffs to Black Shark. Expect some 5-10 fps drop when running Flaming Cliffs compared to Lock On, that is when flying the more advanced flight model for the SU-25T.
My take on it is, that flying the helicopter is much more interesting than the SU-25T, at least it is radically different from the fighters you already have tried in Lock On. Plus you have the fantastic clickable cockpit to play with as well.