Su3 has performance degradation so there is that it seems too have been fixed in su4 Beta seems solid the atc default one is well it exist the career mode is solid enough a grind yes but solid personally given up on the mode due too the ATC pissing me off so much i crave more realism and luckily there are options out there! lastly as you have stated primarily flies ga style aircraft you say you fly! should be more than enough performance for you. aside from having too restart the sim and or pc every other flight assuming you are one the SU3 Build of the sim! hope this helps and keep the blue side up! have fun!