This thread was started on the COLLINS Multi Scan Radar, some of the posts may be referring to the Honeywell RDR-4000.
The Honeywell RDR-4000 Multi Scan Radar is quite different to the Collins one and their features and performance are not the same.
For example RDR-4000 does not have a conventional manual mode. In manual it only gives a Level and not a conventional tilt angle. I believe the Collins manual mode is more conventional.
Anecdotal evidence is that the Collins MSR is a better radar.
The Honeywell RDR-4000 requires a lot of guess work outside 40nm which leads to some needless diversions around "weather". There is a significant increase in workload using the RDR-4000 in comparison to the Honeywell RDR-4B and can make stormy nights interesting.
It's interesting to follow an company aircraft with a -4000 when you have a -4B. The -4B will generally give less track miles and leaves you wondering.
I doubt that the increase in fuel burn I have using the -4000 over the -4B is offset by the -4000's weight saving.
Maybe I'm just not up to speed with the new high tech systems. What initially looked like a great advancement has been a big disappointment.
Note: The RDR-4000 I use does not have a vertical profile display.