Actually there has been some interesting action on the SNES PSP front.
Ruka (lead to believe) has been making some nice fixes and speed ups to SNES9xTYL in the form of some
updated releases.
Many games run really well on this new version on the PSP. It includes the speed hacks that were originally found in the GBA version of SNESAdvance (and later ported to GP2X's PocketSNES).
Games which require transparencies seem to run really well - my favorite shooter on the SNES Macross Scrambled Valkyrie runs very nicely. The Firemen also performs flawlessly.
You do need to clock some of these games at 300Mhz to get it running well but many games work find at 266Mhz.
As for widescreen issues, I don't see the problem with just setting the rendering to 4:3. I know some people aren't a fan of the bilinear filtering but I don't mind it - I'd prefer to use this and use as much as the screen as possible (keeping the aspect ratio correct of course!)
The PSP version can also run games like Star Ocean, though I haven't tried Star Fox and the like.
Mario Kart seems to run fairly well too. On top of this there is a WI-FI adhoc mode which allows multiplayer gaming. I have't tried this as my PSP owning friends won't "stoop" to playing SNES games.
Snes9xTYL on the PSP has a nice interface and zillions of options so you can customize almost every aspect of emulation.
Despite all this, the GP2X does run some games faster - like Gundam Wing Endless Duel - which is really a damn neat little game.
Anyway, that's my impression. Set flamethrowers to 'stun'.
lol - no need for any flamesuits, that was a pretty good summing up of state of play.
I have CFW PSP & a GP2X, and personally I use the 2X for SNES emu. The main reason is the sound quality. Whilst great on PSP, I find if you do not set the frameskip right (if necessary), the sound also reduces speed which really sounds crap on some games (i.e. the graphics and sound both slow down). I remember this happening on Donkey Kong Country. However, I have not looked for a new version of Snes9xTYL for a good while so perhaps the PSP now has the definitive emulations of snes .. .. . downloading latest version now to try out