John from PA wrote in post #18715555
Over the years I've used nothing but LowePro and found the bags to be well designed so I don't think I would question the strength of the strap. Cushioning however is a different matter. I use the 350 and don't have issues, but likely don't carry the bag more than an hour before removing it for gear changes. In any event I'd provide some feedback. Their customer support is at info@lowepro.com.
That bag gets great reviews and is pricey but unfortunately, based on some web searches, that particular bag is often counterfeited because of those great attributes. Hopefully you used a reputable source.
I am not worried about the strength of the strap. The construction of all aspects of the bag is superb. The comfort is where my issue lies. I bought it from B&H so it's no counterfeit. I've had the bag almost a year and honestly love it. It's the bag I always carry on professional jobs due to the amount of gear it can hold. If I was only carrying the bag for an hour like you there would be no issue.
My issues are with the padding. I would love to use this bag as a hiking backpack, as it's semi-hard shell, built in rain coat, good hip / waist support, and ability to hold a large amount of gear and hook gear to the outside of the bag make it seem like that's what it was designed for in a sense. However, the shoulder straps are too thin, and after some time start to wear on your shoulders if you're not wearing a coat or other type of padded shirt.
I've since looked up some Youtube reviews of the bag, and I'm not the only one saying that the straps are thin. If I could switch out the straps of the LowePro with the straps to my Think Tank Shapeshifter V2, the 450 would be the perfect large backpack.