I haven't been in DCS for a bit but with FlyInside not working so well with FSX and the Vive, I decided to give it a go. There was a big update today and I'm not showing 1.5.4.54596. Axel - I don't recall - does that bring us up to the version you are running?
Anyway, you now are in a hanger next to the SU-27 as you set up your mission. Tool tips in the cockpit are pretty obnoxious as they are a big flyout instead just big enough for the text they contain. There is a whole menu for VR in the settings menu and you can adjust pixel density there. Smooth, smooth, smooth. I got zero judder today. None. Zip. Nada. May have bee where it put me as before I only had it when there were a lot of buildings around - e.g. a near and far city both in view just beyond the airport buildings. And the views were beautiful!
Seems you can't have a zoom on the joystick. I don't remember if I had that before, but even though I can bind the buttons, they don't seem to work in cockpit. Might be the VR stuff locking that out. Spoiled from FlyInside I guess.
Anyway, DCS is a very nice experience now in the Vive. I'm very impressed.