I can't personally vouch for the reliability of Transcend SD cards as I've never used them, but I have heard the occasional report from a few different people that they don't play nice with some digital recorders and other devices. Write errors, won't format properly or the card just unexpectedly goes teats-up. That's been enough to keep me away from buying that brand.
I can tell you that I've used PNY (16gb, class 6), Kingston (8gb, class 4) and Sandisk (4gb, class 2) SDHC cards in my Edirol recorders for the past 3+ years and have never had a single bit of trouble with any of them. On that note, there's a Kingston 8gb, class 4 MicroSD card listed on Amazon and Newegg that comes with an full-size SD adapter for around the same price as the Transcend. The Kingston cards work well with Edirol recorders and, should you ever need it for a device that uses MicroSD cards (ie: Sony M-10), you can use it for that, too.
edit: added SD card sizes and classes