Really cold day, I started at around 2 from Inspiration Point. Trail was pretty clear and non technical, views were amazing. Wet spots from the night before. I wore a 20ish lb pack, definitely could have done without it, all I would have needed is a 500ml bottle and a couple of gels.
I ran alone and only used what I had in my pack. Took some video, but they need editing.
It's pretty well trafficked but I wouldn't have done it without bear spray. The north rim trail between upper and lower falls was roped off so I had to detour onto the roads. For me, I think sub-2 hour is doable. Real runners might be able to tackle it in 90 minutes.