I bought the cheaper version cable for about $6 and it lasted about 3 days when it literally fell apart in my hand. Also, the cheap version took longer to recharge both my Vita and the portable charger.
The one I'm reviewing is the original Sony brand, in the Sony box. I've heard of people getting knock offs, so I suggest you buy it from "Amazon" and not fullfilled or third party. Directly sold and shipped by Amazon.
Nothing much to say, the cable is perfect for my needs. I needed one to carry around for when using the portable Sony charger and it works. It measures 3.30" and it exactly as the one included with the PS Vita. Good luck.