I have this accessory and I find it's uses are limited by the offset of the bearing form the bit. It is great for some stuff maybe copying outside edges of a piece over and over, but I like the use of template guides better for copying.
Check out this thread, especially the post by Brice Burrell demonstrating use of the accessories for the OF 1400 router which also fit the Of 1010 router. http://festoolownersgroup.com/index.php?topic=2722.msg29580#msg29580
[Sorry, I don't know how to post a link to another thread.]