I have a 200 ARC that runs Kalyway 10.5.1 and the Kalyway 10.5.2 Combo Update pretty well. Tried to install a few times (unsuccessfully) until I guessed that the image of the ISO might have problems (it did). With a new disc, the installation was pretty smooth. The stock wireless Intel 802.11b card didn't work, but I exchanged it with an extra card (Atheros 802.11b/g) from a dead Toshiba A65 series notebook, and it was immediately recognized and works perfectly. I upgraded RAM with a 1GB stick, so now have 1GB + 256 MB total. Sound playback, w/built-in speakers, works...but mic/headphone jacks do not. Sleep doesn't work, no battery indicator. Office 2008 works well. Safari and Firefox work great. iWork and iLife do not work. iCal doesn't work. I upgraded the hard drive (to 120GB IDE), created 2x60GB partitions, and have the machine dual booting OSX and XP. But OSX freezes on boot about a third of the time, so it's not really a reliable machine...more of a science project and learning experience, so I bought an inexpensive Toshiba (A205-S5804) for $449 at BestBuy, upgraded to 2GB of RAM for $70, and now have a dual core OSX machine for $520 which give me 98% functionality. The 2% that doesn't is mic/headphone jack (yet) and some aspects of power management. Rock solid (hasn't crashed once), all apps run, wireless works (with some tweaking), USB bluetooth recognized without any tweaking. My next purchase: Macbook Pro. OSX is great.