VGC Batman Origins: Blackgate week 1 sales posted.
http://gamrconnect.vgchartz.com/thread.php?id=171379&page=1
Vita 28,028
3DS 17,387
I do think more mature themed games will perform better on Vita regardless of the userbases and this is why Vita isn't always necessarily a bad choice of format to release your game.
Incidentally, 3DS and DS versions appear to have obliterated the Vita version of Lego Marvel in comparison :) and dem Pokemon sales.......!!!