No need to book this in advance as there are plenty of stuttle services around. Even the motel you come to in Turangi can book you up on the day you check in. Also you can have very flexible return pickup if you book through the hotel and so don't have rush down the mountain to catch the last return bus. It is a ripoff charge but we travellers have not been left with any choice if we want to go up the mountain.

Depending on the weather could be a bit hard, but it is really worth it.

This is just transportation but don't miss the transalpine crossing. It's a whipping! One thing is that I wish they were better prepared at the end parking lot with more buses as there was a huge wait.

The shuttle did exactly what they said they would do. Given that it seems difficult if not impossible to get to the start of the hike using your own car, this is a reasonablly priced service to facilitate the hike.

Well organised and efficient service. We booked the Ketetahi option, which means you get somewhere to park getting around 4h limit and a shuttle bus to the start of the walk, they include a map and a few words of wisdom. They do know the conditions and advised us against a later start which proved to be sound advice - so listen.
The walk itself offers excellent views and photo opportunities, the terrain is mixed and I'd say it's a medium to hard trek which could be much harder in bad weather conditions.
For me it would be 5-Stars apart from the fact the route was very busy at least on the day we were there and felt a little overcrowded.
Unusually for this type of walk there are toilets on-route - but remember to take your own paper.

Quite a difficult walk when not trained. Actually not really difficult but really long: I needed 8h30 you can see some people saying I'm not sporty and did it in 6h30, I think they are lying about the not sporty part ahah.
Not really interesting when the weather is bad! low clouds hiding the mountains.

Pick up was on time we actually caught an earlier bus which was a huge bonus. The driver was great and the ride was safe and quick to the starting point. Pick up after the walk was disappointing as we waited 45 minutes and were exhausted so we just wanted to get to our vehicle. Looked like the company had several busses on the road so this was a bit surprising. A heads up that the finishing point of the walk is only a couple of KM's from where we were picked up, so if you wanted to walk it you certainly could back to your vehicle. The hike itself is fantastic and something you MUST do if visiting the area. Took us 6.5 hours at a relatively quick pace.

excellent trip, all worth it !!!

They picked up on time and the drop off too.

This was an excellent trip. Transport pick-up worked perfectly. The walk itself was wonderful, with a view into the volcanic crater itself as well as the spectacular volcanic scenery and lakes.