I don't have any complaints about the people I spoke to in the Book Tekapo office. Coordinating with them and picking up / dropping off the key was a breeze and they were super responsive.
Just know that you are staying in what seems like a brand new construction. It looks like the entire neighborhood is brand new. The house seemed unfinished in a few aspects and felt like it may have been rushed to the Airbnb market with the minimum requirements so the company could start generating revenue off the property ASAP. Nothing major, but just many little things seemed to imply that nobody from the company had ever tried staying a night at the place. There weren't hooks in the bathroom to hang towels and no shelves to hold soap or shampoo. We had to put everything on the floor. The fridge opens really awkwardly that made it difficult to use. We also experienced the A/C unit leaking into the bathroom which makes me wonder if something was amiss in the construction. I think with a few modifications this place could be really great but right now it needs a few more finishing touches.
On the bright side, everything in the place is brand new and there are 2 gorgeous balconies with views of Lake Tekapo and they make an awesome spot for stargazing.