I'm really curious what exactly the culprit is for Alyx's stuttering. I originally played it at launch using Link for my first playthrough with decent performance and occasional stuttering and then switched to VD and the performance was flawless, this was around the first week or two after Alyx's launch. Then when I returned to it months later it was a stuttery mess. I hadn't made any hardware changes so it has to be either an update to VD, Alyx, or Steam VR that's doing it. I've tried multiple suggestions from here and on reddit between VD settings, Nvidia control panel adjustments, etc but the stuttering remains, and for some reason Link is now giving godawful stuttering with Alyx as well.
I know ggodin (VD dev) said Alyx had some issues in VD that needed to be worked out but that was back in the first few months around launch, and I'm not sure if they ever figured the problem out. If its a Valve issue that's pretty frustrating considering their track record of fine tuning games to have excellent performance. And that's the weird thing, it did have great perf...at launch. It's typically rare to see a game's perf gets worse post launch especially from them :/