Sign me up to the DE razor club!
I converted about five years ago, and it made a huge difference to me. As Eoin said, I changed my whole shaving routine at the time, which helped, but the single DE blade also plays a major part.
Beard hysteresis was seen as the way forward, and was the start of multiple blades, but is probably the main reason people get sore necks/in-grown hairs. I just usually do one pass with the DE razor, but if I've more time a second or third pass will give you a real smooth shave.
As for carry on luggage - the blades are specified on the list of objects not allowed - so I bring everything else and pick up a pack of blades at my destination or at the airport. I have a cheap travel razor I use for this.
John - if you find one of these cheap razors (Gillette ones with plastic handles) they will work fine to get you started. That, the blades, and some Palmolive soap should be available in most chemists. After that you can start looking at places like shaving.ie