Without wishing to comment in detail on any given waste collector, there are a few key issues you should always check out.
(1) Do they have a collection permit allowing them to collect in your area? Any reputable collector will have this, but the onus is on the householder to ensure that the collector is duly authorised.
(2) You may wish to ascertain precisely what type of recycling and recovery is being carried out - i.e., where do they bring the waste, and where and how is it recycled?
A good environmentally responsible waste collector should have no difficulty in providing such information.
As a more general comment, there have been instances where recyclable materials, because the consist quite largely of paper and card, have been composted after extraction of metals, and used as "daily cover" in landfill. This practice is liable to be scrutinised by relevant regulatory agencies as it may not be fully in line with national policy which is that recycling is a preferred activity over operations which might potentially be described as recovery or disposal activities. It is possible that such a review could in the future have an impact on the operations and pricing profile of some waste management companies.