I have been playing medal of honor with Vd and its worked well for me. I tried the air link and for me it was a little smoother and a little more stable. But the visuals were noticebly better on vd enough so, that I didn't want to go back to the air link. Airlink adjustments that were allowed didn't up my visuals. I have a 1080 ti. It would be interesting to hear other member experiences.
I've used both Virtual Desktop and Air Link with my Q2 for the past few days. I have used VD with my Q1 for about a year now, and still use it w/Link and VD. Both seem to work well for me and for the most part they are pretty well as good as Link (with my official Link cable). I have a rtx3090 so that probably helps as well.
Tracking seems the same to me (maybe not as good as Link though). Both are very smooth, but maybe AL a little smoother, almost stutter-free. Latency is a 15-20ms higher with AL but I don't really notice this.
My Q2 with MOH and HLA with VD and AL the visual clarity close-in seems about the same but VD seems a little clearer (less blurry) on distant objects. Both games are playable on either platform. My Q2 with Link is also a bit better with distant objects than AL, maybe a bit better than VD.
Pretty hard say which one is best right now because AL has just been released as an experimental option imho. I'm sure that Oculus will improve it a lot over the next few months. Still, nice to have options, esp. when one of them is free!
It has to be the difference in cards. You having a 3090 and me a 1080ti. But like you close up they're both clear but further for me vd is more than a little clearer. My gameplay is effected when shooting enemies further away in air link but not so with the clearness of vd. If I turn up the built in tools of airlink it becomes distorted for me. I'm sure it would be good with a better card which you can't get right now, which I wouldn't get just to use airlink. With vd my games look beautiful. But when I played pavlov the airlink handled latency noticebly better with lower visuals for me though. Vd is playable with pavlov but the latency bothers me enough where I'd rather play pavlov shack where its clearer and no latency. If cards were available and there were enough pc adventure games (only do sims occasionally) maybe I would get a better card which would allow me to use al or vd to its max, but there just aren't enough pc adventure games for me that would tempt me. Especially with psvr 2 coming out. I have given up using the link cable all together since the visuals for me were comparable to the airlink.