So, a few weeks ago the 16gb memory card in my VitaTV suddenly died, even though I almost never used it (mainly as a consolized PSP).
This convinced me that all official memory cards are ticking timebombs, so now both my Vita and VitaTV have custom firmware + SD2Vita adapters.
The process was actually quite simple and the adapters are fairly cheap, so I recommend that every Vita/VitaTV owner do it for themselves.
Not only does it enable the use of the SD2Vita, but it also offers lots of other nice features such as: a PS1/PSP emulator that's better than the official one, a utility that might fix some of the Vita's battery issues, a command prompt that can be used to move/copy files around, among lots of other stuff.
In case anyone is worried that they might lose access to PSN, I've been spoofing the latest official firmware and have had zero issues thus far (can still access PSN store, trophies, leaderboards/online play, etc).