going by other forums, these drivers are meant to be more stable for Gf4's with minor decrease in performance(very small if system is setup correct).
Performance wise upto the 29.42 they have gotten most of what they can from testing with Gf3 (shading, texture loads etc).
Hopefully we will see major performance increase with much later release of Dets. Thats why I am staying at 29.42.