My thinking is you can use a Chuck at either voltage 3.7v or 6v (or more if you dare I guess, but not recommended). So I'd rather have the option to switch it up if I want. With a Little Chuck, you're at 3.7v and that's you're only choice. I'd feel like I was getting more for my money.
True, another reason though is I want something not so big so I can show off in public