I still prefer using a Link cable with msfs2020 and I get very good results, even with my now pretty well retired Q2/rtx4090. I think the visuals are a bit better with both my Q3 and QPro, but performance is about the same.
All work well with Air Link using 200mbps dynamic bitrate but I do get a few compression artifacts that I can notice when looking up at some cloud formations during dawn/dusk flying.
I have recently tried Virtual Desktop and with VDXR, high graphics, hevc 10bit at 150mbps, and ssw on. The overall graphics are slightly better than Air Link and there are few compression artifacts thanks to hevc 10bit. Performance is about the same = very smooth. The only thing I don’t like are the artifacts I see when looking through my heli’s rotor or plane prop. VD is still a very good alternative and it will mainly come down to personal preferences as to which one you like to use best.
To answer your question about going to a Q3; If you cannot get good smooth stutter-free performance with your Q2, I don’t think this will improve by upgrading to a Q3. So, I think you need to work on your setup/settings with your Q2 before thinking about upgrading to a Q3 (or Q3s).
I suggest you try ALL the settings I have listed in my best Link settings thread. This is with a rtx4090 but should work fine with your rtx4080. My cpu is an i913900k and I have 32Gb 6400 ram. I’m not sure what your cpu/ram is but hopefully it’s similar. I use the same settings for both Link and Air Link, just different encoding bitrates (650mbps with Link, 200mbps dynamic with Air Link). Same msfs, Nvidia (currently using 560.81), and win11 settings with VD btw.