Super undies, do you like them?

[Vivhop98]

My DD is so interested in using the potty and has done it a few times. I am trying to decide if I should invest in trainers yet (she is 21 months). I have really been eyeing the super undies, but wanted to hear your experiences with them. I need something that will still hold a lot since she isn't regularly using the potty yet, but need something she can pull up/down and these look really nice. I am just trying to decide if they are worth the cost and how many do you think I need? TIA!