Wow, thanks for so many replies and insights! Great suggestions and comments, all. You all have given me great stuff to mull over.

I should have also stated that I'm on a road bike, 18 lbs., live in hot Arizona, and commute 14 miles one way. I do carry my lunch, an additional water bottle for inside, and a change of clothes. But I also have other stuff in my pack that I take everyday.

So impressed with the photos and videos that have been provided. I've checked out all the products mentioned here. I very much enjoyed reading all the posts on panniers and trunks. The idea of putting the backpack on a rack is also intriguing as well as a Donkey Boxx-like carrier. And the idea of a messenger bag. I'm still checking out the other backpacks, panniers, and trunks referenced here.

I'm going to re-read all the posts again to glean more perspectives. Keep them coming if you would like to contribute your 2¢ worth.