Most of the laptop bags wear out pretty quick if you carry a load in them (such as an old heavy laptop). I use to constantly go through them. I finally found a good one made by Samsonite and still have it many years later.
I had the same experience with back packs. I've got a really heavy "HP" computer back pack that has held up pretty well. One of the better computer back packs I've seen had the Swiss army logo on it but I have no idea who made it. A friend of mine had one of those and it held up real well for him. I would expect Jan sport to hold up as well.
Just expect to pay a lot for any quality back pack that's going to constantly carry a load, and even then it could go to pieces. You just stand a better chance if it costs a lot more but that's not a guarantee.