Actually if you want, I have an SGS and Desire Z both running the latest and greatest (beta ICS or stable 2.3.7 with MIUI).

You can chroot ubuntu on those and do most* linux tasks. Or switch back to a fluid phone experience with over 48GBs of HD Apps, N64, PSX, GBA and SNES on the GameGripper or Sixaxis (I'm not so into NES, Sega, DSi and Dreamcast games yet).