Bento Box has been my preferred method for distance rides. I used to have a handlebar bag but didn't like the way that it increased wheel flop on my old bike. You need to have a fork with pretty generous rake and a front rack to make the most use of a bar bag. Bags that just clamp to your handlebars promote wheel flop due to having the weight all cantilevered off the front of the bike.

A mapcase/pouch that sits on top of the handlebars isn't a bad option either, since it doesn't affect handling, but it's a little more tricky to retrieve items from that versus a bento.

For storing food that I'll need over 50 mile segments, bento box + jersey pockets have been perfectly fine. Everything else goes in the Carradice saddlebag.