I sprung for the DAC 2 to DAC 2v2se with the femto clock upgrade a few weeks ago and the unit has been back in the system for about a week now. This isn't the upgrade you asked about, although if you can afford it, I would recommend you go for it. The difference is quite noticeable, even my wife noticed the improvement right away. I was a little concerned that for the money the improvement may not justify it but this was clearly not the case.
Robert
Robert