Like its contemporaries, Cosmos is also moving from OLED to LCD, which has the benefits of full RGB sub-pixels for each pixel, which reduces the screen door effect (SDE) compared to a OLED, but also means worse contrast ratio, which is most notable in dark scenes. The screen door is not invisible, but it’s a pretty prominent reduction compared to the original Vive.
While HTC says Cosmos’ lenses are new and improved, they take the same Fresnel approach as seen on the original Vive and Vive Pro, which means they show glare and god-rays in the expected high contrast situations.
From my time with the headset, unfortunately it doesn’t seem that the new lenses have done much to improve the notoriously small ‘sweet-spot’ (the area of the lens with maximum clarity) of the Vive headsets. While an IPD adjustment means you’ll be able to dial-in the proper distance between your eyes, you don’t have to look very far from the center of the lens before the world becomes annoying blurry.
The sweet spot issue is compounded by the headset’s not particularly encouraging ergonomics.
Also like Rift S, the Cosmos head-mount seems to give you two mutually exclusive choices: comfort or clarity. When I put on the headset for the first time, I naturally dialed things in to get the best view through the lenses. It wasn’t very long before I started to feel a lot of pressure on my forehead and wanted to reseat the headset for better comfort.