I've noticed that when I install ACE on my Windows 7 machine in the location "c:\Program Files (x86)\VstPugins\u-he\ACE" that there is also this empty directory created: "c:\Program Files (x86)\u-he\ACE".
What's it for? I recall that Zebra used to put it's data in "c:\Program Files\u-he\" but since v2.5 the installation it doesn't anymore because it works the same as with ACE and it's data directory resides in the map where it's dll is located (which I do find more convenient). So that makes me wonder why ACE should have to create a second data directory there now.. little bug perhaps?
ACE is great sounding and much fun by the way
Do you plan to update ACE (not meaning the "big brother" of ACE and Bazille projects you are working on) in the future? An arp like Zebra's would be very interesting to have on board if I may kindly suggest 
Thanks!