I have the 40 litre and I bought the padded seat also .
Have used it in France a few times in August when fishing for a month in over 40 C heat and it performed very well .
Obviously keep opening it to a minimum helps but I was well impressed .

In reply to Post #15
Absolutely agree with that, you'll need arms like popeye once its loaded up, you'll be glad you didn't get the 55L .

It's arrived and looks great, looking forward to using it in a few weeks.
Thanks everyone.