I recently bought a Playstation Vita and I love it. The only thing I don't like about it is that it doesn't really have a wide selection of games at the moment. Also, the price is not that reasonable. It needs to be dropped. If the handheld system costs more than the actual console then there's a problem there. But there are a lot of features with the PS Vita that really drew me to it. Luckily I got mine for a bargain price. However, I have never owned a Nintendo 3DS so I can't really comment on it. I've never been interested in the Nintendo 3DS which is why I never bothered to buy it.
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