I have thought of another question, so I'd like to toss it out as well for comments....

I'm planning on using a small'ish backpack to transport items to and from work with me (tablet, lunch, book and or magazine) and I have one that I've used a few years ago when I was more into hiking than I am nowadays. Even though it's somewhat small, it is made from a heavyweight material, so I guess the question is....would I be better off buying a new, lighter weight backpack that may help wick away sweat, or do you think the old one would be okay for a 4.5 to 6 mile trip?