I was thinking about the absence og great games on PSVita when I realised ROBLOX would be the perfect game for it!
The Vita has two analog sticks that allow for more precesive and less frustrating movement than for example the iPad.
It also features a multi touch screen that allows for pinching and interaction with GUI elements.
The hardware is also very good.
Packing a quad core processor, a dedicated graphics chip with 128 MB of VRAM and 512 MB of regular ram it should be powerfull enough to run most ROBLOX levels even without the new featherweight parts.
The controls, portability and hardware make it a very viable platform to play ROBLOX on on the go. Since it is a device primarly made for gaming, it would offer an overall better experience than it's smartphone competitors.