This is a very fast little Memory card, well worth the purchase.... my old memory cards' read speed was 10MB, but this memory cards' write speed is 10MB and 15~MB read speed....
This Memory card works perfectly with My Xperia, and is a real memory card, and the SD adapter also helps with file sorting, and ease of use. I also like to use the SD card since it also makes response times of the memory card faster, and thus I can get copying things done quicker
If you are suffering from a really really slow memory card, I would recommend the upgrade, and at only £15 you can't go wrong...