I've been doing more and more long distance rides and I've really been considering going clipless as I've read and people have told me it makes a huge difference. The thing is.. I still occasionally run errands on my bike and switching pedals to do so would be kind of a hassle. Carrying a pair of shoes with me is always a possibility.

Are clipless shoes that uncomfortable? I've been told moutain bike shoes are a bit more comfortable to walk in.. are their any disadvantages to that?