Yeah, every droid is definitely different. Personally, I had no problem clocking up to 1.2LV w/ Chevy's Froyo kernels on Kangerade, although 1.0SV seemed to be the most responsive and stable...now running CM RC2, the only ones that get past the white circle "M" are jdlfg's, up to 1.2. The 1.2 is snappy as all get out, but my battery life is a little less than I like.
I thought I remembered reading that CM's ROMs have a different boot.img or something along those lines and not every Froyo kernel would work, but then I come on the forums and I see that you guys are rocking the Chevy kernels with no problems.
Man, its frustrating. I guess I'll have to keep experimenting or flash to a different ROM - although CM is by far my favorite with all of its tweaks and I would rather optimize it than flash to something different.