If you are looking for a good carrier for an older child, I would recommend a soft structured carrier like an Ergo, Beco or Patapum. My second choice would be a mei tai. IMO, it depends on how you want to carry your baby. If you are comfortable with a back carry, I'd go with a soft structured carrier. If you are not and want a front carrier only, I'd get a mei tai. Both types of carriers can be used for a front, back or hip carry but I think the mei tai is best in the front and the ssc is best on the back.
If you will back carry, the soft structured carrier just cannot be beat for comfort. It has a thicker padded waist band than really distributes the weight well. I carried my 20 mos old in my Beco almost the entire time we were at Disney last fall. I did again when he was 2+ in May (although he was more willing to walk/stroller ride then). I had no back or shoulder pain at all. They are just super duper comfy. It's not my fav for a front carry b/c the waist band is wider/thicker so it's sort of a weird fit for me with a front carry, but I have done it and it works fine, just not as well as my mt.
The mei tai can be used in the front or back but for me it's best on the front. It does make an excellent back carrier, but it doesn't have the super supportive waist band so my shoulders and back start to ache after long term carrying. It cannot be beat as a front carrier. Far more comfy than a baby bjorn and much better for baby as it holds your baby in a seated position rather than the hanging from the crotch position.
If you have an older baby and are going to do so long term carrying at Disney, I would not get a ring sling or a pouch. I have both and love both but I could not carry my kids for hours on end at 9 mos old in a one shouldered carrier. They are awesome for quick trips to the grocery store, etc. but a two shoulder carrier is far more comfy if you are going to be walking Disney, standing in line, etc.
FWIW, I LOVE my beco (
www.ecobabies.com). I also have a patapum and I really like it as well. I prefer the Beco b/c it's made of beautiful material and it has a taller body. The Ergo is an awesome carrier as well. I don't have one but the moms who do, love them. The body on the Ergo is much shorter than the body on the Beco. You cannot go wrong with any of these carriers. If cost is an issue, visit the for sale or trade board at
www.thebabywearer.com. You can find excellent deals on previously loved carriers. You can also find tons and tons of info on babywearing there!