[ONE General] notyu1459:
Mine has been wonderful. This is the only phone of mine that has ever ran Dreamcast games smoothly. In fact, the only issues I have are emulator related, not device related. With a GameKlip, its a wonder to use.

The only kernel that has given me smooth performance so far though is Franco Kernel. With all other kernels, I get frequent large dips in framerate on Reicast. On Franco Kernel, it works just fine. CM11s or AOSP, it doesn't matter.

I will say, though that the ROM and kernel I recommend overall is Slimsaber 9/12 and Franco Kernel r18. I miss some Cm11s touches, but until they fix all that needs to be fixed, I ain't switchin' back to a Cm11s based rom.

EDIT: I'm Currently testing Slimsaber 9/22 and Franco Kernel r20,. So far, so good :D

EDIT2: AAAUUGGHH NEVER MIND!!! GRAPHICAL ANOMALIES AND TOUCH ISSUES EVERYWHERE AFTER 3 DAYS OF USE! Going to try upgrading to the new 9/25 build to see if that fixes anything.

Other ROMs I've tried:

JEDI Open Source Project (r1.0): rock-solid, but not fully compatible with Franco Kernel, and the kernel that came with it gave me the same frequent large dips in framerate as every other kernel except for Franco Kernel when using Reicast.

CM11 Temasek Build (9/22, with Franco r20): Seemed like the scrolling was a little rough, butI I thought I was seeing things. Nope; scores in Antutu Benmark plummeted, even when everything was set to maximum performance. Also, it got really hot :(

Remember to always clean flash!

This is my Experience with several different emulators:

Dreamcast (Reicast): Near perfect. Tiny dips in framerate that don't affect the gameplay at all.

A tiny amount of missing textures and missing/glitchy sound effects. Most 3D games work fine (The only one that was unplayable was Zero Gunner 2, which ran quite smoothly but suffered from major graphical issues), all 2D games have major graphical issues, rendering them unplayable. Hoping that the Reicast developer fixes these issues, because it would be really nice to play Mars Matrix and SFIII, which both run smoothly but suffer from major graphical glitches that make them undecipherable.

SNES (SNES 9x EX+ Super Hyper Turbo Remix Deluxe): Beautiful. Fantastic. Amazing. Honestly it rivals an actual SNES.

N64 (Mupen64plus): Several graphical issues in several games, but smooth most of the time. Banjo Kazooie runs fantastically with practically zero graphical issues, which really surprised me. The only completely unplayable game was Conker's Bad Fur Day, which is a pain in the ass to emulate on any system. Most, if not all, of these issues can probably be fixed in updates to the emulator.

PS1 (FPse): It kinda......just works. And it's tons better that playing PS1 games on the PSP, and even rivals the Vita when used with a GameKlip. No complaints at all, really. Except it won't respond to input when playing Darius Gaiden (at least when I tried it. I think someone out there is deliberately making it difficult for me to play this game on the move. I couldn't even test if the music worked, because it wouldn't respond to button presses. I can tell you that the music doesn't work at all on the PSP, and even if you got it to work, you wouldn't be doing the game justice, anyway.)

Genesis/MegaDrive (MD.emu): So far, no significant issues. Speed is not 100% sometimes (and by that I mean the emulator runs a little faster than its supposed to where there would be slowdown on the console. Not a huge issue). Sound is not perfect, but surprisingly accurate; more so than most other emulators I've ever used on anything else. And Thunder Forcee IV doesn't crash mid-level like on a PSP :D

Have not tried NES, PC-Engine, or older consoles, because frankly I have plenty of other less powerful devices that can run these games just fine.

So, how have your emulation experiences been with the OPO? And what kernels/ROMs have you tried? I'd really like to know, going forward. I have a feeling that this device will be top tier for emulation for a while, even in the wake of 805 and 810 processors. It's remarkably well put together in both software and hardware, and unless someone releases a Snapdragon 805 or 810 based phone with a 1080p screen, little bloat, and expert hardware and software implementation, this device will remain relevant. :D