The 3DS specs a lot more better then you think.
The Vita uses an AMD CPU for a 4-core 1 GHz CPU
The 3DS uses a non-AMD CPU for a 2-core CPU
both handhelds are underclock for battery life, but the 3DS is the first Nintendo Handheld to be build entirely around the battery.
The PICA200 is a series (2006 & 2008 & 2010 & 2012 models) and the 2008 model has a Vertex Performence of 40.7 million polygon @ 100 MHz, when the 3DS GPU (whichever model) confirm to be clocked at 400 MHz.
I have the whole debate/discussion on this thread: http://gamrconnect.vgchartz.com/thread.php?id=169468
Check out the OP of my thread.