I have the Passporter in the leather 3 ring binder. I had the spiral but "upgraded. Here are the pros and cons as I see them.
3 ring is better because you can move days around without erasing everything. If you decided to go to MK on Thurs instead of Wed, you simply move the page. In the spiral you have to erase it all to move it. Or have your days out of order.
3 ring is better because it holds more. I have certificates, DD's etc. in mine and it is bulging. The spiral one wont hold it all.
3 ring binder IS heavier and bigger. However, my plan is to just take only the current days page with me to the park in my fannie pack. It will have my itenerary, PS and all certificates to be used for that day inside it.
If you need for some reason to carry all of your information with you for all of the days, I wouldnt get the leather binder. It is like a dayplanner and would take up a lot of space and weight.
JMHO,
r4suns