So already I know it performs better than the 2 gig kit of PC2-6400 Reaper I had, which would not boot at anything above DDR2-960 or so, and wasn't stable above DDR2-950, even with the timings loosened to 6-6-6-18.
My first attempts were with the timings at 4-4-4-15. DDR2-849 was about as high as I could get with solid stability. I loosen the timings to 5-5-5-15, and got all the way to DDR2-1059. To be honest, I was just hoping to get the ReaperX to DDR2-1000, but I still had plenty of room left. I loosen the timing to 6-6-6-18, just to see how far it could go. No luck. I raise the voltage to 2.15, then 2.2. DDR2-1059 is the highest I can get the ReaperX stable. I'm quite pleased with its overclocking performance; getting over 32% overclock at stock voltage is pretty impressive.