Hayden Beckwrote a review of Black Diamond Speed 40L Backpack on June 21, 2017
Familiarity: I've used it several times
Different iterations of the Speed 40 have been around almost as long as I have been climbing (8 years!), and for good reason. Using this bag, I can see each area where they have improved upon previous designs.
This pack is just enough to carry some pretty burly loads (i.e. hauling all your stuff into basecamp) yet it is easily strippable for lightweight missions. I usually roll without the lid and padding on the hip belt for spring and summer climbing. If I am going to be on a route for a long time, I will remove the aluminum frame sheet too. But when its time to carry something heavy, (like bivy gear or skis)I can easily convert the pack to heavy lifter mode again.
As a poor college student with way too many outdoor hobbies, I need my gear to be as versatile as possible. I have used this pack for numerous different mountain sports: Ice climbing and ski touring in the winter (the bag is the perfect size for yurt trips), and for rock climbing and backpacking in the summer (some folks may find it a bit minimal for backpacking, but it suits me just fine) I have even used it to haul a huge, heavy mess of highline equipment on a recent City of Rocks trip. If I had to own only one bag, this would be it!
I haven't had the pack for that long to comment on the durability. The areas that see the most wear like the bottom and under the compression straps (where ski edges rub into the fabric) seem to be doing fine so far. I will add that this is an alpine style pack so it won't be totally bomber, but compared to other ultralight style bags I've seen/used, this one is way more rugged.