you'll see that the 3200+ venice compares somewhere between the level of a pentium 2.6GHz (northwood) and the Pentium 3.06GHZ (northwood).
I guess price is always a consideration, AMD 3200+ retails at £101
whilst the simillar Intel chips from the guidee above retail at £143 for the 3GHz P4, (and I couldn't see [at a glance] the price of the 2.6 on Dabs).
Generally, it's safe to say that the Intel 3GHz chip has a slight speed advantage, et a slight cost disadvantage. however, since the speeds and price are so simillar I'd literally hold off (if cost were such an issue that the £30 increase was too much) to get the full Intel setup.