1- no return time limit means more flexible than a FP. I can use it at lesiure if doing other things... including..
2 -no return time limit means I can stack multiple DAS cards and still use the times efficiently
#2 works by having multiple people with DAS cards in the same group. You can stack as many rides as you have DAS cards in your group. Then you bypass the 'can only have one time' limit by using a second card.. and have no risk of having your first card's return time invalidated by being late. Do this, and you can move from attraction to attraction with little to no wait inbetween. The only 'cost'... have more than one person with a DAS in your party. The DAS holders ride as 'guests' on the other DAS card return times.