Usual warnings apply to anything system oriented
, but I have used DriverMax with the early builds of Win 7 without issue. I went x64 some time ago and DriverMax has only just started supporting 64 bit hence my not using it for a while.
With the WinSXS size issue i only found out when trying to help cut down disk space usage on a Lenovo laptop with a fixed 30GB system drive. It initially seemed an ideal candidate for moving to a separate drive, (by using a Symbolic Link, strangly enough), but further research found the truth buried in technet