Hello all,
I carried a briefcase for my entire thirty years of work as an urban planner. I occasionally tried using a rucksack when I had a lot of papers and reports to carry. I concluded that it was more practical to use a large briefcase, rather than a rucksack.
I have carried various rucksacks and backpack for recreational purposes for close to sixty years. I don't recommend rucksacks for business.
I continue to use a briefcase for business, or business-like occasions.
On a trip to Paris a few years ago I needed to schlep stuff while out and about. I wound up buying a a somewhat hip-looking soft Patagonia briefcase with a shoulder strap that I continue to use for travel and for business stuff.
Gurdon