Msata is a smaller format that is typically reserved for laptop motherboards, and sometimes used in desktop computers primarily for OS storage to increase boot speeds. I don't know off any benchmarks off the top of my head but I do know that Sata is updated significantly more then Msata and does have faster transfer speeds and more bandwidth. If you are considering a SSD for a desktop i'd recommend a traditional for factor in lue of an Msata as it cost more and requires a Motherboard with a Msata port.
Money is not a problem for me and my computer does have an msata port. I am running two HDDs and was thinking about upgrading 1 to an SSD. Do you suggest I replace 1 HDD with an SSD or get an MSATA and keep both HDDs?