When I first received my WO scope I found out how great it was to rotate the eyepiece into any position without having to loosen and rotate the diagonal. A bit too loose on the diagonal or not quite tight enough when re-tightening and bang the diagonal and eyepiece can hit the pavement. Not to mention the rotation marks on that nice diagonal barrel. With the CAA you can rotate the eypeiece (or camera) to any angle and gain a comfortable viewing postion. This is a must have in my book. Be aware that it will add a bit of length to the focus tube, so take that into consideration if (in) travel is an issue.