Yup nForce2 is clearly better but if there's a decent price diff KT600 is actually VERY close. nF2 support AGP/PCI locks which can help o/c'ing but then it's pretty pointless unless you plan to stray above 216/432FSB which has VERY minimal gains over 200/400FSB anyway. nF2 supports Dual Channel DDR which gives it a 5%ish perf boost, it is this which takes it just above the KT600 and there are vers of nF2 without DC-DDR so be careful. Of course you need 2 sticks of RAM to use it so you probably pay 5% more for the priviledge and it does often limit your RAM/FSB upgrade paths too. nVidia certainly have the better sound, VIA Vinyl still isn't implimented yet, nVidia's sound chip can be omitted from some nF2 mobos so again do check if you want good sound. No mobo should have any trouble unlocking TbredB or Barton (TbredA is crappy) because they're already ALWAYS unlocked. Some dumb-a$$ mobos get confused with mults above 12.5x (5bit FID) but I hear that can apply to nF2 as well as VIA chipsets. Some things nF2 really have going for them is consistency, stability, compatibility and more mature drivers, VIA chipsets are often problematic. As said SATA150 is far better on KT600 but I seriously doubt it would impact speed as even ATA100 isn't truly limiting perf. So nForce2 are best but not by a whole lot, price diffs may be small though but do check your mobo has all that you want.