By far the best and most reliable portable drive I’ve used is the G-Raid series by G-Technology.  I have 4 of them, some are 4 – 5 years old, and they all still work great.
Internally, G-Raid has two 3.5″ SATA drives that are striped together using RAID level 0 for speed. Â The stripe management is all handled inside the box. The mac sees it as one volume. Therefore if you have a 500GB G-Raid, inside is two 250GB drives. Â These arrays are very fast and can handle multiple streams of DVCPRO HD. I edited a show in FCP at 720P and never experienced any drop frames. From a reliability standpoint I’ve never had any hardware problems with them but have seen the typical mac volume problems. However I’ve never had any data loss from it.
G-Tech now has a version 2 of this drive with ‘Triple Interface’ FireWire 400, 800 and USB 2.0. Newer drives get up to 2TB capacity for under $550.
Now let’s examine the disadvantages. Â The main concern is that with 2 drives striped together you are risking up to 2TB of data with twice as many chances of a hardware failure. Â If either of the two physical hard drives inside the box die you lose all the data on both drives. If you’re using them for media and have the tapes as a backup – it might be an acceptable a low risk. Â Like I said, I’ve never had data loss.
As part of my “moving forward” theme (out with the old) I’m trying to lower the risks of data loss. I will most likely be selling my G-Raid drives in favor of a larger safer total solution. Since this solution will likely be based on a sata connection, I might keep one for transporting files.
There are other newer G-Tech solutions such as the G-Speed which I’ll talk about another day.