Sorry for dragging up old threads but....
I work as a joiner and after dropping my oilstone (I now have two oilstones
) a few years ago I bought a diamond hone, I can quickly get my Plane irons (blades that is) and chisels shaving sharp with it.
I have dropped it a few times and it's still fine and it lives in my toolbox and gets battered about a bit.
I don't think I will ever go back to stones nowadays and just about all the lads I work with borrow it if they can.
Japanese waterstones sound like a good idea for the workshop but not much cop for site use let alone for out and about camping and so on, and I wont even go into the half a stone idea.
About the only thing to remember about diamond hones is to make sure they are fully before storing them.
Just my take on the deal anyway.