Here is a 2012 Macbook friendly accessory to stuff in your travel bag. A Newertech (Newer Technology) USB 3.0 to e-sata adapter. This device retails and sells for about $30. You can probably find other adapters cheaper from other brands but Newertech has a great reputation for Macintosh capabilities.
My only real gripe is the short USB cable with both A end piece connectors. You can't simply use a different USB cable if you want to.
The reason I got this cable is that many of the current/existing e-sata/usb 3.0 combo boxes are flaky with USB 3.0. I've looked at over a dozen different makes (Mediasonic, Sans Digital,etc) and models. I've read hundred pages of forums and reviews (Amazon/NewEgg) to know USB 3.0 raid enclosures are iffy at best. They drop connections, sleep causes issues, transfer speeds are problematic, there are chipset incompatibilities,etc. I have a few boxes and docks where my Macbook Pro's USB 3.0 port does not work. An example is the Voyager Q HDD dock.
I tried this cable on various e-sata devices and it works great. I get about 180 MB/s reads and 160 MB/s writes which is about correct. Most e-sata boxes in RAID or SSD top out at 200 MB/s. With some USB overhead, 180MB/s reads is pretty respectable. The only thing faster for a Macbook is Thunderbolt.
Overall, I am happy with this device.
A short summary for those interested:
- Plug-n-play operation. No drivers needed for OSX.
- Not bus powered. Does not support esata-p
- Respectable USB3/e-sata speeds.
- USB A to USB A end cable.
- Does not support port multiplier.