I'm going to Fry's tomorrow and buying a memory card for the PSP. So I've read that depending on the reading speed of your card, your games may load faster or slower or become choppy? Is there a huge difference? Fry's has a $40 Lexar 8gb card, and DX has an even cheaper one. Sony is a bit pricier, being in the $50-60 range. Is it worth it, or does it not really make much of a difference?