We found this studio to be a good option for a couple of nights in Kaikoura. It has the basics of what you'd need in terms of kitchenware, towels, toiletries etc and was clean. The self-check-in via the lockbox was also really handy.
As clearly stated, it is right on the State Highway 1 so do expect to have large trucks travelling past 24 hours per day. That said, I used ear plugs and didn't hear them through the night and I'm generally a fairly light sleeper. I think the price also reflects the fact it is in a busy location.
We found the bed to be quite soft/bouncy (although not terribly uncomfortable) so that could be a problem for people with back issues.
We also had an issue with the WIFI not working - the main router for the building is in the upstairs apartment and it seems there was an issue there but neither the owner or ourselves had the ability to sort it - it relied on the upstairs guests to reset the modem and I think they were out at the time. The owner, Emily, did respond promptly to my request for help with the situation but it wasn't sorted out during our stay. If guaranteed WIFI is a major requirement for you in terms of your accommodation, then this setup may have the potential to be problematic.
Other than that, the hosts provided really clear information and stressed their availability to assist with any issues which was great.