You nailed it though - and I experience the same. I went from an Oculus Rift CV1 to a Samsung Odyssey+, and landed on an HP Reverb, which is superior in clarity to those HMDs I've owened thus far.
With that in mind, I have no issue with readability in the Viper, either.
In fact, my go-to for VR readability testing is flying the Christen Eagle II from the backseat, and if I can read the speed gauge decently well (which is not that close to the pilot as you might be aware of) I know that I am pretty much set for most of the DCS modules I own in terms of being able to read the most important instruments.