I think I have read most or all of the posts on the retrofit door, but most I found are older. It is time for me to upgrade older gold line units. At this point, have the credit card readers been working smoothly. I have been told I need the DAN, another source says no. I think Roz has a lot of experience with the doors, but his older posts are no longer taking replies, it appears anyway. Any experiences with the doors, or even the Commander, would be a help with the direction I go, Thank you.