I bought my 2nd one the 6L and it's the perfect size for my Sony A6400, two lenses, batteries, charger and hang a carbon fiber tripod using two straps to the bottom of it. Perfect for travel and the way the strap works is awesome to keep it close to your body. Added the clip to mount the camera on to change lenses and take the camera off of my neck, just amazing products.
I have the 3 litre Everyday Sling and use it a lot. It holds my camera (Q2 with grip and finger loop) and spare battery, SD card, and Nitecore charger and a few wipes etc. For travelling around with the minimum and safely, it is second to none; it is so small and light, it weighs so little, keeps the rain out, has excellent padding, allows me to quickly grab the Q2 out and take a snap and put away again without a palaver, it has a nice Velcro separator that keeps the battery and charger and bits away from the camera. Almost perfect... my only gripe is that (like the other peak design bags/packs/pockets) it uses a metal zip fastener that can cause scratches to your gear if not careful. I know metal lasts, maybe have some sort of cover/hood/sleeve thing that the fastener can be tucked into so it's not exposed?
Although I am not a photographer nor do I carry any cameras/camera equipment I love this bag. I use it to carry my electronics, water bottle, and other necessities. The versatility of this bag is impeccable and the quality is top tier.
I bought this as a small “take anywhere” bag and it works well for that. Everything is a compromise and this bag is no exception. I like that it’s padded and weather resistant but the compromise is the clamshell is a bit more cumbersome than a flop over design.
Bought the 5l sling and it is my trusty side kick, it is minimal and keeps my Canon R6 and RF15-35 safe! After a good 2 years of use, the zip gave up. I contacted customer service, it was a straight forward process and PD followed through with their warranty claim. I am so pleased to receive my new 6l sling! I trust no other company with my camera gear. Seriously the best investment that I have made. I also own an everyday backpack, pouch, a few slides, capture, cuff and the carbon tripod.