The VIA K8T800 / 8237 is a LITTLE faster on average and has working SATA ports in the southbridge.
The NF3 150 had some problems with SATA and some other things so the VIA is winning, IMO, right now. So I hope the 250 is better as they may have the AthlonXP chipset tied up, they are not #1 in teh socket 940/754 department