I would never trust a leaked build pre-launch for performance benchmarking, people doing that are just trying to get clicks.
The dev process is crazy, different for everyone, and that build could have been before a huge performance tuning pass for all we know
I think i was close to 400 when i started going for completion, and then i played more RIGHT up to the 400 mark and quit until sote, now I'm getting close to 600 and I'm just exploring and fighting hippos, I'm actually really pumped to get into ng+ now, i haven't done any of that yet for some reason.. in ds3 i was like ng10 lol