100% secure is the biggest LIE!
I had one and it crashed - ALL my saves are LOST.
Never buy anything else then ORIGINAL Sony Memorycards!
Use the USB Stick to save them on your PC if 16MB with two cards are not enough or use only 1 Max Memory Cards in the second slot if you need to access a lot of saves. But keep in mind, that it can loose its data.
This was not only my Problem, it happens to many other users on the Internet! Just use google and see...