Problems I had with them: (1) Overclocking (as you've mentioned) was very poor. (2) K8T890 lack of dual-core support (link). They fixed it later, but it would have been nice for it to just work (as Nvidia did). (3) Lack of SATA-2 support from some Via southbridges (link) which require the drives to be forced back to SATA1 mode. Again, this didn't happen with Nvidia chipsets.