Just the map and public opinion, there are some steep/slower sections and the 'face' track is a bit rougher.
While the summit isn't far or any huge elevation gain, the boulder jumbles will take time.
And time will fly, given the extensive views... then it's not unusual to see runners, opinions will vary widely.
I'd say 6-8 walking hours fast/average?

(Back via Wombat Pool will return you to Dove L ..)