Anyone with a 60GB or larger SSD shouldn't worry about this, install Windows 7 to a SSD to take advantage of the SSD read/write speeds there.
Regardless of what i imagine SuperCache does, profiles, registry, temp files, etc. will touch the system volume at some point regardless of what you try and do.
Ramdisks, as this is really under the cover, were popular many years ago before SSD's, because of the speed you could get. Ramdisks are simply dangerous to most users who don't have a UPS because of the data loss which can happen on a power cut/loss.
The answer, Get an SSD larger than 60GB and don't worry about it, Look at the last board the Z68 and a feature called SRT that Intel plugged to business' hoping they would buy into multiple drives for boot times and putting temp files somewhere basically, really just buy a good quality SSD over 60GB and use it.
Thats my 2 pence, hope it helps.