Likewise, I really don't want to use my 4000 cu in backpack as a daypack.
That's how I used to think. But there are plenty of packs that have short frames and cinch down enough with compression straps so that they're not too bulky or too tall to use as a day pack. Kifaru Longhunter is one. The good thing about using your backpack as a day pack is you're never lacking for space and there is no trip back to camp to get the big pack. Plus, you don't have the extra piece of gear to pack in.
