Not in VR surely? Certainly not with the HUD info overlay turned on, which drains frames in a torrential fashion! ;) What level AA? Do you use the dynamic res setting? The scenery detail multiplier?
I settled on High, no distant scenery multiplier, 2XAA. Not sure what method the AA is using, or that it even works that well but 4X seemed to hit me right in the performance.
Using .8 dynamic res so it at least stays smooth when the HUD gets turned on, figuring I'm mostly checking the map anyway so blurrier scenery/closer draw distance is acceptable whilst its open. The Rift Async Spacewarp feature seems to be working, even though the game runs via SteamVR (I can see it lock down from 90 to 45 fps occasionally) but it's still smoother with variable res active as well.
I do wish there were some actual graphics options beyond those presets so we had a bit more control. Not sure of the difference between High and Ultra but generally in VR I've found Ultra to be overkill - usually worth spending frames on AA or supersampling instead.
In general it does run very well though and feels great to fly, but like DCS things get a bit sketchier when low amongst the buildings.
DCS runs similarly well for me these days, though this is the v2 beta using Nevada. Have yet to try the old 1.5 Crimea map on my updated PC. DCS always started to bog down when adding more foes, it's pretty heavy on the CPU - IL2 does seem better in this regard.
The IL2 map is nicer at height, great view distance, lots of vegetation (though camera-facing branches are obvious in VR), sharp features like rivers and roads, great atmospherics. I think the audio is better as well.
(Btw I've been testing in what looked to be the most performance intensive map area in a quick mission here)
Click for pic