SSD obviously is better. Transcend has announced the arrival of a new SSD, the MSM610. This SSD is a little different from other mSATA SSDs, as it might feature slightly older technology as well as coming in an even smaller package than the standard mSATA SSD.
But if you want to decide between those two, here is two links for compare:http://www.harddrivesforsale.com/st31000528as.html
You can see specs of these drives, as well as customers reviews. Up to you what to choose