The Petzl Bug is a solid contender with no stand-out features. It has almost all of the features we want and is the most comfortable contender in the review - when both hiking and climbing comfort are taken into account. It's below average in both weight and durability.
Performance Comparison
The Bug in action on Yak Peak.
Weight
The Petzl Bug tips the scales at 18 ounces. Nothing on the pack is removable, so this is the weight users are stuck with. We wish at least the pack's hip-belt was removable. The Black Diamond Bullet Pack weighs the same but has more durable fabric. Our testers suspect that it's the Bug's well padded back panel that has it looking plumper than most of the competition.
Durability
The base is sewn of sturdier stuff, but still inferior to the bases on the Patagonia Linked or BD Bullet. The main external zipper is comparable to the one found on the Mountain Hardwear Hueco 20 and smaller than the strong one on the Bullet. Our testers were disappointed to see wimpy hardware in such a crucial location. We are somewhat reassured by the flap that protects it from damage. The two compression straps are unique in our test and feature small buckles that are an odd size and variety. If the male part of one buckle were to break a replacement would be hard to find.
If a climbing pack's main compartment is closed by a zipper it should be a big burly one (Bullet, left) or at least covered by a flap (Bug, center). The Hueco 20 (right) has the smallest and weakest zipper.
Climbing Utility
The Bug has a reasonably solid feature set. It has one exterior pocket that's roomy but hard to get into when the pack is full. The generous internal zippered pocket is where the key clip lives. The sternum strap buckle does not double as a whistle. This pack has one unique feature: the topo pocket, which lives in the back panel of the pack. Though it does hold and 8/12" x 11" piece of paper well, our testers found it more useful for stowing the shoulder straps.
The Bug has all the standard hydration system features, except for a loop or clip to secure the top of a hydration reservoir. The Black Diamond Creek is also missing this. Our testers found that this allowed 2 - 3L reservoirs to flop around (unbalancing the pack) or even fold over (compromising water flow).
Without a clip or loop to secure the top of a hydration bladder, it can flop around or get squished and cut off water flow.
Although this bag lacks dual haul loops, the main haul point can be backed up using the top loop of the daisy chain. It's inconvenient, yet possible, to tuck the shoulder straps into the back panel pocket to streamline hauling as well. The hip belt has its own dedicated slot in the back panel to disappear into. The pack is reasonably streamlined, the only place it could get hung up is on the compression straps.
The 18 liter capacity of this pack is contained inside a simple rectangular shape which made packing reasonably easy. We found it less challenging than expected to retrieve something packed away in the bottom. Like the other bags we tested, it works fine on straightforward, half-day, multi-pitch routes. However, it also has enough capacity to accommodate longer days or carry-over objectives.
Versatility
Functionally this pack has a few deficiencies in versatility. For carrying inside an overnight bag for use as a summit-only pack, it's heavier and bulkier than the Linked or Trango Ration and gets the job done about as well as the Hueco 20. It's also more than capable of toting around a laptop, serving as a daypack for hiking, or any of the other things a small backpack might get used for.
Attaching a single mountaineering axe to the outside of the pack requires some rigging with the single daisy chain, connecting a pair of ice tools is trickier. The buckles aren't particularly glove-friendly, another limiting factor in the Bug's potential alpine career.
On the approach with half the rack, helmet and 70m rope.
The Bug's rope handling top strap is complemented by the compression straps. This offers the best rope containment solution of any pack in the test. The Arc'teryx Cierzo 18 also offers good rope retention, but its cord compression system is more complicated to use.
Comfort
The Petzl Bug's basic rectangular shape and slightly curved shoulder straps do not scream "ergonomic climbing comfort" to our testers. Nevertheless, our testers enjoy climbing with this pack on (as much as one can enjoy climbing with a pack on). The Bug is also comfortable on the trail. Part of its high weight is caused by extra padding in the back panel, which makes it more pleasant to wear. The only pack in this review that is more comfortable to hike with is the Metolius Mescalito which has an impractical amount of padding for climbing.
The three most comfortable packs in our test: the Creek 20, Linked, and Bug (L-R). They were chosen for their comfort both on the trail and on the climb.
Best Applications
This pack shines in multi-pitch situations. It's small and maneuverable enough for near-your-limit gymnastics yet versatile and expandable enough to stuff for committing in-a-day big walls. If you're searching for a pack that works for any long rock climbing objective, and you don't thrash your gear, then give this one some consideration.
Value
The Bug sells for $70.00 MSRP. This is about double the lowest-priced REI Co-op Flash, but in the neighborhood of the other models, we tested. We think you can get more pack for your dollar. If you like this bag, but you're on a budget, search for sales.
Conclusion
The Petzl Bug is a comfortable climbing pack with a reasonable feature set. It's also the most comfortable pack we tested. However, its relatively heavy weight isn't offset by any benefits in durability. Comfort alone isn't enough to make this pack stand out from its peers.
When climbing with the Bug our testers rarely noticed we had it on.
