The 3DS is the better console in pretty much every way imo. I'd even say the lesser specs are maybe beneficial for a contemporary handheld. It just doesn't look like the whole portable Ps3 idea ever really worked out. I think it's tied to the gaming habits. Portables need to be shorter or segmented gaming experiences to entice people in who like game in short bursts. On the commute, on a break at work. Etc etc.
The idea that next Sony handheld, had the Vita been successful, would allow you to be playing something like Witcher 3, FF15, MGS5 type games seems just a misguided idea. Those games need long sessions of dedicated gaming.
I would suggest that's part of the reason the Vita hasn't really worked out as they hope. Though it is very good as an indie machine.