Collections are quite intensive with a strong focus on security. Typically you will be collecting from Banks and Government Agencies with the odd retail customer. Most collections are "out of office hours" so you will hold keys and alarm codes - lose a key and lose your job!!! Depending on the location you could have up to 25 collection points to be completed in a 3 hour window and the pressure is on to return to the local hub on time, as feeder departures are extremely tight.
As a new starter you would be almost certainly used as a reserve so expect to work all sort of hours - unless you can get a firm commitment to assign you to collection duties only I would think again, unless you are prepared for some early starts.
The one positive, although I work permanent nights on a feeder run, I never see a manager more than once a year