I just flashed ARHD 9.0.0 over ARHD 7.2.0 without clearing cache, without factory reset, without clearing data and without Super Whipe script.
Everything went just fine and ARHD 9.0.0 runs without any problems!
By flashing this way I kept all my programs, settings, etc. (I only needed to re-install 3 programs after the flash, that wouldn't start-up anymore. That was it.)
I've done the following:
1) Backupped all my programs and settings with Titanium Backup (Pro). - I didn't need this, but it's better to be safe than sorry!
2) In CWM made a full backup of the ARHD 7.2.0 rom - I didn't need this, but it's better to be safe than sorry!
3) Flashed boot.img
4) Flashed ARHD 9.0.0
Finally, after booting the rom for the 1st time, I've installed the %-battery mod from Jotha.
Like I said; I encountered no problems, so if you're on ARHD 7 or 8 you could give it a try without clearing data. Of course there are no guarantees that this will also work flawlessly for you! But there ain't much to loose, since you can do a Super Whipe anyway, might you run into problems.
Mike, thanks a lot for all your work!