The benchmark results clearly show that if you really want a high-performance external hard drive, then you should absolutely go for eSATA and nothing else. FireWire 800 delivers much higher performance than USB 2.0 or FireWire 400, but it still doesn’t get anywhere near the nice results that eSATA offers. We found our real-time file read and write tests particularly interesting, as these illustrate the performance differences very clearly. It takes roughly a minute to copy 1.5GB of video data with USB 2.0 while the same process required only 15 seconds with eSATA.
If you do not copy gigabytes of data very often, then it is obvious that you do not need to worry about these performance results as much. USB 2.0 should thus serve your needs, since it's so much more convenient and, in fact, available on the front of most PCs. However, others who needs to regularly transfer anywhere from 50GB to 500GB of data will immediately realize that eSATA really is a must-have.
Let’s look at some numbers: copying 300GB of video data via eSATA onto the G-Drive would require roughly 50 minutes. If you were to do the same task with USB 2.0, we’re now talking about much more than three hours--and this is only for 300GB of data.
However, there are significant price differences between convenience-based storage products, such as the SimpleDrive III and the professional G-Drive at 1TB. The first costs roughly $200 while the fast-and-flexible drive is as expensive at $199, which also means that a 2TB multi-interface drive will cost you in the neighborhood of $349. USB 3.0 could change this, as the interface delivers even higher bandwidth than SATA 3 Gb/s. But it will take some months until USB 3.0 storage products will be available at a lower cost than the existing combo drives.