Originally posted by ZaphodB 3) I wouldn't gain much significant benefit from the smaller lens size, because the lens would still be mounted on a chunky modern dSLR.
Now number 3 in that list is obviously the main problem... for me it rather cancels out the 'unique selling point' of the pancake lenses. [...]
Here's another advantage -- they're small when packed, too, so you can easily fit them into a very compact travel kit or day-shoot kit. If your typical-use lens is a telephoto zoom, you can throw in a wide-angle pancake without much thought.