Just to clarify, in Manhattan you have:
- Fully-staffed HLE locations (most, if not all, in parking garages)
- Garage locations with 24/7 kiosks (regular Hertz cars with daily rates; basically, a HLE without live human agents)
- Garage locations with 24/7 (fka "On Demand", ffka "Connect") cars, which are billed by the hour, like a Zip Car.
Some of the fully-staffed locations have a semblance of Gold Counter service. The location at 55th Street in Midtown is pretty nice, with three agent terminals and a waiting area. The one at 445 Lafayette is little more than a single person booth in the garage. I've found them to be pretty reliable on the whole; I have had odd occassions when they were short of cars or were having computer problems, but overall, I like the service.
I've not used the kiosk locations as I prefer to deal with the counter staff for my regular Hertz rentals.
The service for fka On Demand is not as reliable as the regular Hertz service.