I hate database on the C:drive as well. I have it on the D:drive, therefore it is backed up when I back up data.
I have done it both ways. I like Detach and move rather than just detach and then copy as, if I recall, it moves the correct folders and databases. Of course, you simply reattach after. I would do a backup of your server and of AC just to be on the safe side.
Once, I just bit the bullet and installed to D. I guess in that scenario I would prefer the program on the data drive rather than the data on the system drive. But, of course, there is the silly backups going to the AC folder automatically, although I do have them removed automatically.
