We just spent 5 days at this unit. It was a bit out of town but, unless you love relentless crowds and hunting for paid parking, it is better to be out of town.
No big problems, easy to communicate with agency via email and they respond quickly. Of course, they are available via phone for urgency but we had no need to call.
Suggestion to take this to next level. Perhaps leave a few Bin bags-the unit had one bag for 5 day stay. Cheap thing to do and avoids overstuffing bin bags. And put a small broom in the unit for gentle tidying (and it might make the after visit professional cleanup a bit easier).
All in all a very good stay. If you are looking for a place to stay in the St Andrews area, give it a try.