What's the best portable emulation device at this point? Anyone using the new Google

I used to have the first PSP and used it to run NES/SNES/Genesis/CPS2/PS1 emulation. It worked pretty well but now I want something newer/faster and preferably with a bigger screen. My requirements are that the device must be smaller than an IPad and it must have a D-pad or the ability to connect a PS3 controller via bluetooth. My coworker bought a Google/Asus Nexus 7 tablet and it can run emulators really well and you can pair a PS3 controller to it. Is there a better option out there? I know a couple years ago some asian companies were making dedicated emulation devices (game park, wonder swan, etc) but they seemed like they might be of questionable quality. What's the best option out there right now? Should I go with the Nexus 7? Is anyone else using one for emulation and have any feedback? Thanks!

Well i'm mainly using my mobile phones for portable emulation.I have a Nokia E5 (Symbian s60v3 Snes,Nes,Mame,GBA,GBC,GB,Genesis,DosBox,ScummVM) and a samsung galaxy S2 (android and a lot of emus) as for the emulation devices i don't know.
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