I'll add that the concern for my deposit isn't totally unwarranted.
Before I rented rhis place it had been many, many years since I last rented. There were several times when I never saw my deposit back at the end of my tenancy (despite never missing rent, or leaving any damage to the property etc).
The last place myself and my ex rented (before we bought a house) we lost our deposit (to a private, pie faced, wealthy landlord I recall very well).
No issues with this agency (I've never actually had any contact with the landlady who owns this flat) btw, it's coming from past experience.