Up until the latest patches for these two aircraft, they ran very well indeed with FI XP and XP11, but unfortunately, the latest patches created an issue that led to what is commonly known as VR-freeze, in both aircraft. this is where the whole scene moves when you move your head and believe me, even the most hardy of VR users will feel their stomach wobble a bit if you leave your headset on for any length of time. there's a challenge for you.
There is a temporary solution, which involves disabling/removing a plugin called TGDS, which sits in the aircraft's plugin folder. Although this plugin only controls the display of the weather and terrain on the ND, that will of course no longer work properly. FF are supposed to be fixing this, but they allegedly started looking at it in July and when i check a couple of weeks ago, they had made absolutely no progress at all. Their devs are probably currently concentrating on the changes that have arisen/are arising out of the FF A320 beta