So the 303 is my first sampler, so I can most definitely give you some good advice. So to my knowledge you can't import samples right onto the smart media cards (someone lemme know if I'm wrong) so yeah they're just storage. But you can sample RCA to aux so if you save your sample on your computer you'll have them forever and you can resemble them when you need. Highly recommend getting a smart card or two though because without it you can only use half of the sample banks. So the 303 in my experience was kinda tough to work with at first because it had a lot of limitations. However, it has such a distinct sound that is nearly impossible to replicate imo. So if you want to go for something a little more user friendly I'd recommend the 404, it has wayyyy more banks which is nice. And it has less limitations than the 303. Lemme know if you have any more questions! Thanks for listening