I've used backpacks since the beginning. On grocery trips I wear two, one on front and one on back. This can easily total 65 lbs, which I seem to be able to handle OK.
I will likely get a crate and fasten it to the rear rack, but I am wary of the handling changes when I'm all ready going from a super stable cruiser to a commuter layout with shorter handlebars & related less leverage. I may change to a slightly longer handlebar eventually regardless, but not 100% sue about cargo quite yet.
We'll see what ends up happening. If I do switch to bike vs back, I will follow with an update!
- Andy