Yea, I've seen some SLOW cards in my day. Not fun to deal with especially when trying to build an array with a huge number of drives with lots of space. I also don't like the fact that some of the utilities they come with are so damn laggy, you are sitting there for hours trying to get anything done within the card.
Mostly safeguarding the audio/video materials from my band described earlier, plus I'm acquiring a fair amount of files to be shared, I cant just use Acronis to backup and compress it and hide it away, I call upon it quite often for many reasons. Another thing being that this is my first step into advanced storage techniques, my first experience with this I wanted to start small. Once I learn more, if my needs grow, so will I. I'm already planning another build for my recording studio at the end of the year and those raw audio files take up lots of space. I could use that as an excuse to upgrade later.