I also intend to use an Exos 58 for many reasons.
(1) I used it on a 267 mile walk on the Pennine Way with much the same stuff that I will use on the camino. (I have also used it on about 3 other over 100 mile walks in other parts of the UK, and use it as a day walk bag.)
(2) It is a very light, strong, and ventilated bag that fits my back just right.
(3) It can be cinched in to fit the amount of gear inside so if you have little in the bag it can be pulled in tight around the gear inside.
(4) I already own it, and have absolutely no reason to spend pension moneys on another bag, that would be wasteful in my eyes.
(5) The top lid pocket can be removed,( the lid flap can then be deployed to cover the top of the pack), and reduce the temptation to pack it with extra stuff taking the capacity down to about 53 L
(6) It weighs in at around 1 kilo 0r just over 2 lbs. Shoulder straps are very comfortable and waist belt though not the biggest or best does its job adequately and takes the weight off the shoulders .
Antis
(1) the temptation to pack more than needed just because you can. that is down to self discipline.
(2) the waist belt padding although OK for me could be a bit better padded for people with bony hips. Wear a soft fabric trouser belt with this bag if you are lucky enough to own such hips.I
I may feel differently after a 500 mile camino, but hey, you start out where you start out from.
As an aside I use a large water proof bag inside that only carries 40l anyway and then I never need to deploy a rain cover. using this also creates a packing discipline. That bag could be a bin liner or a specialist stuff bag which is what I use due to its strength.