I've used an Osprey Kestrel for 3 years now, however i wanted something lighter, more comfortable and preferably with a ventilated back system. The Exos covers all bases, and as expected the build quality is second to none! The bag itself is very light, and carries very well, it feels like a day bag, but swallows seemingly endless amounts of kit! The back system is incredibly comfortable and you really notice the vented back panel. The straps on the bag are all stretchy and vented, and work exactly as they should! There are so many great features on the bag, but the one which stands out for me, which is often overlooked is the pocket configuration! The pockets on this bag are really well thought out. The front stretch pocket is really handy, and the two mesh side pockets are excellent to get to drinks bottles, but the pocket on the front with the side zip entrance is an incredibly useful pocket which now houses all the kit i need access to quickly ! An excellent bag, which i think is going to provide many years of service !