Set out around midday on a hot and sunny winter Sunday from the Maritime Museum. The road crossings were a bit faster on a Sunday but the popular park bits required some navigation around groups of walkers and children.
I'd intended to do the round trip FKT, but felt sick quite early on and even worse near the end of the north-to-south leg, so i slowed my pace further and called it good enough once i'd reached the sea at Onehunga Bay.
As most of the previous route-runners have noted, it can be a bit challenging to follow the exact route at Mt Eden and One Tree Hill -- i wasted time backtracking 3 or 4 times -- generally the issue is that the original route file's GPS wasn't quite accurate enough to identify the subtle turns necessary.
Additionally, there were works and path closures at both key parks. At Mt Eden that forced me onto far trickier grass/dirt next to the closed road (seems it will be closed for a while due to repaving), and at One Tree Hill it was the opposite, with a gated grassy path being taped off (seemed more temporary) and forcing a return down the paved path.
After the climb to One Tree Hill, the last 4km of the route are largely downhill and could be done quite fast. At that point i was legitimately concerned about making it to the end without some kind of accident, so i jogged it instead to be gentler on my stomach.. this turned out a very wise decision as the public toilets at Onehunga Bay were closed, so no pit stop would have been possible had i continued on my originally planned round trip.
Food/water (unsupported) -- my own water and snacks had been intended to last 3h30-4h, so i didn't need to stop for any water/etc. along the way. In the end i went through just 500ml and 1 gel, as my stomach wasn't feeling up to more.
There may be some drinkable water in the restrooms of one of the main parks. To the south of One Tree Hill you run past a few shops and restaurants, so could conceivably stop if you needed supplies.