I have an AMD system with NForce 2 and I have the option to chose from corsair pc3500 rev1.1 platinnum (BH5) or ocz500256el-ge (I think hynix 4.3ns). I have an NF7-S with I do not intend to Vmod, wich one should I choose, both are same size and price...
I guess it depends on whether or not you're going to seriously overclock your machine. The Corsair will run at 434MHz with timings of 2-3-3-7 on most likely 2.6V. The OCZ will run at 500MHz with timings of 2.5-4-4-7 on 2.8V. I know that some motherboards can handle a 2.8V Vdimm; only you know if yours can.
I'm sure that if you lower the FSB to 400MHz, the Corsair will run at 2-3-2-6 or 2-3-3-6 at 2.6V. For some reason OCZ says that even if you lower the FSB on their modules, you might not be able to tighten the timings.