I have been using a Shuttle AV-40 with the VIA P4X266. I am very happy with the performance. I can overclock to 116 FSB using CL2 and 118 FSB using CL2.5, with a P4-1.5G running at 1.74/1.78 GHz. I got this OC result using one stick of Mushkin 512MB Special. I have two more sticks of Crucial 256MB which does not OC as well. Worst, when I tried using all three DDR sticks, the best OC I can do is 105 FSB. (The momory is running at FSB+33MHz) It demonstrates what AT talked about stability in the i845D roundup. BTW, the AV-40 is absolutely stable using a single Mushkin stick.
I am looking for the next upgrade, the Asus P4S333 looks attractive, but I am not convenced yet. The DDR333 is not such a big deal since the increase in performance is small. In fact, when I compared the Sandra memory score, the VIA using agreesive timing does as well as the SIS at 333 since SIS does not have option for more agressive timing.
I consider the ability to OC to be more important. AT showed that the 845D can be push to beyond 140 FSB. GamePC showed the SIS 645 limited to 115 FSB. Are there more definitive answer to the OC capability comparison?