The threads Pro vs. Pro II seem to come up every so often and they're often argued by comparing features vs. cost. I can hardly believe that any Pro owner switched to the Pro II when it was released just for the new features. The most striking difference IMHO between Pro, Pro II and Pro IID is their age: the Pro was released in 1982, the Pro II in 1995, the Pro IID in 2004. Like with all technical devices, age doesn't tell you everything about their condition but sure tells you something.