2 sets of TCCD myself, results on DFI NF4 Ultra-D:
OCZ 4200EL Plat, 2x512: 270 2.5-3-3-7 with 2.8VDimm
GSkill LA's, 2x512: 290 2.5-3-3-7, 2.7VDimm. Couldn't quite hit 300 with those timings. I did Prime95 them at 305 MHz 2.5-4-3-7 2.9VDimm, just to break the DDR600 stable mark, but I run them at 280 2.5-3-3-7 and pretty good lower level timings 24/7.