I prefer to take my chances and just change my money over there, although we are away in 10 days so any fluctuations shouldn't be as much of an issue for us than someone going in October. For those inclined to change their money before they go though, that is a great tip sueles!
Having the "funny money" in your hand used to be part of the holiday experience for me and I do miss it a bit. I'm not so sentimental that i'd forego a good deal though, and that's what we always seem to get by changing money over there. I'd also guess that it's good for the local economy, but as always it's each to their own