Originally Posted by Aerocat
so if you can't get in off the CDA because there is cloud on profile at the MDA then you shouldn't be getting in off the dive and drive either if, as you say, you are not leaving the MDA below or above profile.
Not quite. If on a close-to 3° profile with cloud at MDA + 20 on a CDA, you will almost always be forced into a Go Around, whereas you could be level at the MDA for a mile before and get in because you are just under the cloud, especially if the vis is OK. All you do is maintain altitude until flying into the PAPI and then descend.
Given the number of times this scenario is actually encountered, CDAs are better. No worries about bumping into/off/thru limiting steps.