I love the style of the Mary Janes, and they are great for walking around town, shopping, etc, but... I don't like them so much for a full day at WDW. In January, I brought 4 different style
Crocs with me for a weeklong trip. I rate them as follows:
1- Beach (Disney style or regular)
2- Cayman
3- Mary Jane
4- Athens (only because I didn't like the flip flop between the toe thingy)
The reasons for the ratings:
The Beach has a nice loose fit, making it the most comfortable for all day walking around. The Beaches stayed cool (no sweaty feet) and they never rubbed or created hot spots or blisters. The sole is nice and thick, so walking and standing on pavement all day didn't hurt my feet.
The Caymans were almost as good- I gave the Beaches a very slight edge because the Caymans are a bit more narrow, so they felt just a tiny bit more warm and sweaty in the heat of midday.
There was a noticeable difference for me in the way my feet felt after a full day in the Mary Janes- the sole isn't as thick and cushioned (and there isn't as much arch support, IMO), so by sunset (after wearing them since rope drop), I could really "feel" the pavement under my feet. I felt the need to sit down on a few occasions because of achy feet with the MJs- never felt that way with the Beach or Cayman styles.
If the Athens had had a thinner (fabric, maybe, instead of foam) toe post, I would have liked them very much. I actually had to change out of them and into other Crocs halfway through the day, because I was developing a blister on my toe from the toe post. If you get used to them, and can handle a thick toe post, they might be the most comfy for you, since they are very lightweight, are open so your feet stay cool, and the sole is a cushy as Beaches.