The lack of a memory card slot in the iPad is a show-stopper failing for me (even before noting that it's obviously a method to enable Apple to charge an extra $100 for 16GB or 32GB of additional memory -- the latter is overpriced and the former is downright highway robbery).
After the theft of my old 40 GB (hard-drive) MP3 player, over $200 on sale a few years ago, I scored bigtime with a $40 4G Sansa Clip player with a card slot. Add a single 16G card and I have all the music on a much smaller player -- and if I want more I just get a second card.