These are designed for DSLRs and from what I can tell do not support playback of video files. They may work for the basic backup but will not really work as a full featured transfer/DIT station where you can QC the actual video. We'd recommend a laptop and either the Sony Content Browser Software (free, optional AVCHD plugin = 19.95) or else a 3rd party transfer solution like ShotPut Pro.
We've been using SD cards on our cameras for 4 years now and have never dropped so much as a frame. Always buys a reputable name in SD cards with the right rating and you should be fine. We then transfer footage to our edit systems, these are connected to a DROBO FS which has 5 x 3gig drives and acts as a live backup and finished productions backup.
"There's no point in filming in you don't have fun"
Incubate Productions South Africa http://www.incubatevideo.co.za
I use SanDisk Extreme Pro Class UHS-I cards and dual record all important shoots to the FMU128 on a NX5U. In 3 years I've NEVER had a problem. I have a RAID hard drive system for archive. After a shoot, I create a folder and label it whatever the shoot was and copy the exact contents of the card or FMU128 to that folder as archive. I then do all editing off of the FMU128. The SDHC cards are, essentially my backup in case there's ever an issue recording to the FMU128.