Mechanical or Optical end stop?

Hi Guys

I'm about to order a DIY RAMPS1.4 kit, but have to choose between optical and mechanical end stops.
There is a wiki page on the topic, but the only conclusion I can make out of it is that mechanical end stops can start failing when it gets old, but it seems that it takes a loooong time for that to happen. Optical is more complex and expensive, so why would you go for that option? There seems to be surprisingly little discussion on this topic, is it because most people just go for the simpler, mechanical end stop?
At the same time I've seen one or two post of people struggling to replace their mechanical end stop with an optical one on the Z axis specifically.
So it seems there is some motivation to use Optical at least in the Z axis?

Thanks in advance
Rudolph