It certainly benefits from experience. The first few pulls are scary, the first night I tried I wound up giving up, but coming back into it with experience and a clear head it felt a lot more doable.
In terms of it being on par with O3S I can't chime in directly as I've never even pugged past O2S. I'm not saying that that invalidates this difficulty comparison but just pointing out I cleared this fight before ever making it past O2S.
Sadly my weapon has yet to drop.
