When Sony replaced the original PSP with the slimmer/lighter models, they took a dive in build quality, and you could feel it. This time, the PS Vita's thinner, lighter model has not only a good solid build, but a few nice tweaks that push it ahead of the older model.
The new rounded shape is nicer to hold, and the PS and START buttons are more rounded, raised slightly, and have a small click response when used. And bonus! The proprietary connector (used by the unwieldy power cable) has been replaced with a simple mini-usb port. You probably own a bunch of cables you can charge it with already.
Listen, fanboys will have a tantified conniption over the fact that the OLED screen has been replaced with an LCD one, but it means a significant increase in battery life and, honestly, it's a VERY nice LCD screen. It's like this: if you are looking at _________ (insert name of your secret crush model/actress), you can probably lose a bit of interest in your girlfriend. It's just biology. But if that model/actress is not about, your girlfriend seems fine. More than fine. The new LED would lose if you compared it side-by-side with the old OLED, but how often will that happen- The truth is, if you bought this and played it, you'd love it. It's fine. More than fine.
There's also a 1gig built-in memory to get you up and going with game saves, so playability right out of the box is on the list.
You're going to buy one, and so am I. You know it.