Exped have given the hugely popular Thunder a massive overhaul and it looks great! Updated style that has resulted in a lighter, tougher and more comfortable pack.
Exped says:
Thunder is a trekking pack with a superb weight to volume/feature ratio. The suspension system is quickly length adjustable and provides excellent fit, torso mobility and weight transfer. Three access options to the main compartment (top, front and side loading) allow simple packing and unpacking. A large front and two side stretch pockets offer additional storage space. A floating lid with inner and outer pockets and adjustable side compression straps increase carrying capacity for extended trips and expeditions.
Exped's 2020 Thunder 50 Rucksack is like a completely new pack. Often, updates simply cover one or two features but the Thunder has had a complete overhaul and we think it's been a really successful one. The look of the pack has changed completely with a slick, modern style now evident. The fabrics used are more environmentally friendly, more waterproof and more durable so there's not much else they could improve in this regard!
The pack retains a number of great original features such as the lid, which provides protection for the top of the bag and has pockets to help you keep organised, the large mesh pocket at the front and sides of the pack, ideal for wet gear quick and easy access. It has also kept the three different access points which allows you to see, pack, unpack and keep your gear organised wherever you are and whatever you're doing. The harness with adjustable back length, well padded hip belt offers comfort, convenience and flexibility.
One issue with both the Lightning and Thunder packs was often the comfort around the lumbar support. It simply didn't suit many people but the additional padding and improved, stronger aluminium frame are much more comfortable under heavy loads and for extended trips. Personally, this is the most important change as I always steered away from the old versions due to the comfort but I'm now using this pack regularly.