An interesting topic.
This exact subject came up several months ago. The debate was similiar and the bottom line highlighted the short-comings of the whole slot system.
We are left with a situation in Europe where many airfields adopt a differing approach to slot management - particularly with regard to the interpretation of the -5/+10 aspect. Local regualtions are plentiful, and sometimes poles apart, and it makes it impossible for flight crews to keep abreast of the differing procedures for the many airfields they visit on a weekly basis.
It is very sad in this day and age that a flight on a route where there are no flow restrictions can suffer delays, sometimes extreme, because flights on other routes have to receive priority because of restrictions.
In a busy Summer 'No Slot Required' can be the kiss of death!
The European slot system is long overdue for a complete and thorough overhaul because I am not convinced it is achieving what it set out to achieve.
I am not spoiling for a fight here - I know you are only working with what you are given.
PS. If anyone has the 'Big Picture' could they fax it in A4 sized pages so I can put it together on a day off?