As a cycle stop I find they are very good, personally I find the coffee pretty good. I do like a good coffee shop but to be honest it depends whats on my route. I wouldn't go out of my way for a McDonalds over a tea shop and vice versa.
In relation to the litter problem, the nature of the product you are buying denotes a lot of packaging, wrapped burger, fries in a box, salt sachets, napkins all then in a big bag and a cup for the drink. The volume of packaging when scattered is going to look very prolific. I'm in East Devon, a designated "Area of Outstanding natural beauty" ( apparently!) and the bloody stuff is everywhere. But also there is KFC, Costa, subway and general foodstuff wrappings that could have come from any supermarket or independent corner shop.
At the end of the day, McDonalds don't throw it out of car windows or leave it lying around, that is down to the end user. People should take responsibility for themselves, I can't see how the chain is at fault for this? Are Benson and Hedges responsible for people not putting fag ends in the bin?
Unfortunately saying McDonalds is responsible for it is another way of moving the blame from the dick heads that leave the rubbish around, if they feel remotely justified in thinking "It's not my problem, it's Maccy D's" then they wont think twice before doing it.