Unreal is a fantastic engine — no doubt about it. I think it’s an excellent thing for the VR community that we have two major engines competing and innovating in this space and I hope the competition remains strong.
Unreal certainly has the reputation for being better if you’re among the subset of companies that have a AAA budget and a main emphasis on rendering quality. However, I’d argue that for the vast number of VR applications, Unreal’s slight edge in graphical capabilities is outweighed by the great increases in team productivity and access to resources and talent you get from Unity.
At the end of the day, they’re both pretty fantastic tools and it comes down to a set of tradeoffs based off of the needs of your project.