I've had mine since launch. 1.80 made it so you can only have one account per card. Previously, you didn't HAVE to format the card after going through the other nonsense.
I have two cards, my smaller one is linked to a JP account. But going through the other nonsense and startup stuff as well as screwing up my folders and backgrounds makes it unappealing. Haven't switched around since soon after PSO2 was made compatible.
It'd be great if the store was universal, even if it locked you out of other regions by default. Like, what if the store was like "Oh, I see you're playing the JP version of Freedom Wars, here let's give you access to that section of the store". Then I'd be like "Sweet, thanks PSN, now I can access content for the game I bought!" And everything would be awesome.
Sadly we may never live in that world =( But at least we can play other region games on Vita unlike 3DS x.x