1. Don't go in expecting anything, just because someone else got it.
2. Follow the A64 OC Guide that's stickied in the AMD section.
3. Post your results/problems, and we'll help you.
there's no difference, just remember you're dealing with two cpu cores now. I've also noticed that if you use cpuburn on both cores to 'burn in' the cpu, the overclock results get a little better.
Active cooling on the pwmic also helps too, dual cores tend to make it much hotter.