Aside from the huge capacity of this single 512 Mb stick (which is good for around 200 5-megapixel shots), the increase in read/write speed you would expect with "Pro" isn't really apparent. In fact, a quick test between an original memory stick and this Pro stick revealed the write speeds are actually about the same.
Still, it's a sensible purchase for getting a whole family holiday of snaps onto one stick. And as newer cameras begin to offer greater resolutions (7-megapixel and beyond), this stick should hold its own for a few years yet.