I honestly doubt that the features that will be unavailable will impact performance. I looked at the asus site, and didn't easily find any info on what might be impacted. I do know that that Xeon doesn't perform as well as a 3570k for gaming, but for programming, it's one hell of a buy in comparison.
I recall reading that maybe that Xeon would fit better in a z68 board though? Can't remember where I saw that unfortunately.