With the PlayStation Vita, you can buy retail game card games or download digital versions from the PlayStation Store. It's your call. But before you do, there's something you should know: one is slightly faster than the other.
In this video from sister site Kotaku Japan, a card copy of PS Vita game Uncharted: Abyss and a digital copy. The card copy is running on the top Vita. The digital version is on the bottom. (Note: Kotaku Japan set one of its Vitas to English as the default language, hence the English language Uncharted title screen.)
It's not just Uncharted. In the second video, the same test is run on Army Corps of Hell. Once again, the top Vita is running the game card, while the bottom one is running the download copy.
The difference is only 2 to 4 seconds. Nothing major, but if you're someone who counts every second you have, then you might want to go with the game cards.
Be sure to check out Kotaku's Vita coverage.