We stayed there twice (Dec 2011 and Dec 2012), both times in the same room (2nd-floor studio)
That is what we liked:
1) Great lake view. Even though a one-story building (a part of the same motel) stands between our building and the lake, it doesn't obscure the view.
2) The place is spotlessly clean
3) A huge balcony, a great place to have a breakfast while enjoying the view.
4)The owner (Bryan) was very helpful, provided a lot of useful info.

What we did not like:
While there is a nice path along the lake shore leading to the downtown, it is a 40-min walk - not practical! This problem is not specific to Reef Resort, practically all Taupo motels stand on the lake shore, away from the downtown.
Overall, both times (2011 and 2012) it was very pleasant experience, if we go to NZ again we will be happy to stay there.

Fairly good views of some parts of the lake, just be careful when having a shower or using the spa because the smooth tiles are a death-trap when getting out with wet feet. There were a few panels that had been removed from the atrium probably for cleaning which made the place look untidy, overall not bad but there is better value for money in Taupo.

Stand-in Managers were extremely welcoming - provided good local information. Room upgrade was unexpected but proved to be superb - very comfortable bed and room well appointed. Excellent view across the lake (despite the mist in the morning).

Spent 2 nights here and were very happy with rooms, they are good sized and have all that you need. Enjoyed having latest mags there for you to read as well. Pool lovely at 28 deg so got in morning and night and the hot pool is also good. Will be back to stay next year.