Emulators on Android phones are superior to the ones for hacked gaming handhelds, but nowadays they come with HD or Full-HD resolution which I guess makes them not so much suited for retro emulation. But I could be wrong though because of the small screen sizes that may make up for it in addition to the various FX options of emulators. I only have 480x800 devices for testing and so far the image quality seems to be ok. What phones do you use for retro emulation and how is the image quality?