My 360, bought in summer 2007 to replace my launch model RRoD system, has been acting up lately. Freezes every once in a while (although this seems to be only when I play Halo 3 with originalz) and last night started stuttering while playing Soul Calibur IV.
So today I went and picked up an Arcade unit for 20,000 yen and will be selling off my Core system tomorrow. Runs quieter and has HDMI to boot...I just hope it's not a lemon.