Ostensibly, the advantage of eSATA is a notable increase in transfer speeds. According to Verbatim, USB transfer speeds sit at 15MB/s write and 26MB/s read, which isn't exactly amazing, but eSATA transfers will whizz along at a much better 25MB/s write and 60MB/s read.
Not one to take such claims at face value, I grabbed a Snow Leopard DMG I happen to keep handy and swapped it to and from an eSATA-equipped computer to the drive and back three times, averaging the result. The results speak for themselves, with real-world transfer rates over USB of 27.6MB/s write and 31.6MB/s read with eSATA providing 40.7MB/s write and 73.6MB read. In other words, eSATA is not only, as claimed, significantly faster than USB (what a revelation) but more impressively also faster than Verbatim suggests it should be - awesome!
That would be somewhat good news for Verbatim, but the OCZ Throttle is cheaper than the eSATA/USB Combo SSD 32GB while still providing similar transfer speeds. The former can be found for less than £70, where as the latter is currently sitting at about £90. Hopefully, this will change once a few more stores get stock in, but for now it's prohibitively expensive.
That's a shame because Verbatim's drive is still otherwise an attractive proposition. The retractable ports, for example, are an excellent design feature and the inclusion of a full sized USB connector, rather than a mini-USB port as featured on competing products, is to be applauded - carrying cables around with a flash drive is an utter chore.
The inclusion of encryption software is another point in favour of the Verbatim drive, too. Run directly from the drive, this applies 256-bit AES encryption to all files placed on the drive, on-the-fly as they're transferred. While this does slow transfers down a little - by how much will depend on the processing power of your system - it does offer some piece of mind if you fancy storing important data on the drive; which with 32GB of capacity you may well wish to. The catch here is that the software supplied, EasyLock, is a 30-day free trial version - you'll have to pay for more use than that. If that software were free with the Verbatim eSATA/USB Combo SSD 32GB, or the overall price were lower to start with it would be a much more compelling buy.
The sliding connectors and the use of a full size USB port are excellent design decisions. However, when other flash drives offering similar connectivity and transfer speeds are available at significantly lower prices, simple common sense should indicate which is the better choice and, here's a clue, the Verbatim eSATA/USB Combo SSD 32GB isn't quite it.