About run-time (not editor) performance, after a ton of setting changes (if you’re struggling and not using nanite
do the following command: r.nanite 0
helped me a ton.
I feel like i’m still not quite there, but it’s extremely close now. I hope it’ll be easier to get similar performance in the future without digging down for commands and things to bring back similar perf to UE4. Will see in release, looking forward to the improvements. Exciting times 
When it comes to the editor, it feels like the same requirements of UE4 to run it. If anything, maybe lighter. I could be biased because of the clean UI feeling though : :