Hello, same question as OP My local store sell both Xperia Play and PSP 2000 at very similar price, and I wonder what device have better battery life and emulation performance (pre-32 bit systems)? I also hear some complaints about the input lag on Xperia Play, does it really true?
I have the Xperia Play, a PSP 1000, PSP 2000, and PSP Go, and I'd recommend the Play if you're looking at below-32-bit emulation. My experience so far is that the Play handles PS1, NES, SMS, Genesis, SNES, GB, GBC, GBA, GG all very well, and it has more RAM and better battery life than my PSP units. Granted, I also have the extended battery for the Play, but considering it's difficult to find a reliable after-market battery for the PSP units at all...
So far, I haven't noticed input lag with the Play. I also see a few people loudly proclaiming about input lag on Android in general (the OS, not just the Play in particular) but I have yet to see anything that stood out to me.
In case you need it, here's a pack with some files that might be useful in setting up a Play:http://www.mediafire.com/file/4a5cs41n9hbn8mw/Working+Xperia+Play+Files.7z
It has the kernel and ROM that I used, as well as a collection of the emulator APK files.