To those who have MRDS experience, what in your opinion of the most robust MRDS?

Feom the research I've done the Trijicon RMR and the Insight MRDS look like the ones least susceptible to cracking from a hit to the dome. All the others like the docter, leupold deltapoint, burris fastfire, etc, are all thin metal around the glass.

Thoughts?

You may be right.  But go to Leupold's site and check out the new Deltapoint Pro.  It is not in stores yet.   I obviously can't vouch for it.  But it has a heavy combat shield around the "dome", much like what they added to the standard DeltaPoint that is mounted on the combat Mark 4 HAMR.

It also has redesigned features, such as a top mounted battery tray, much easier adjustments and both motion detection and automatic light intensity.  i want to check one of those out when they get in stores.  That lens shield looks very sturdy. The entire optic is also very small, less than two ounces.  Here are a couple of pics from their website.  

Looks tasty.  Will be on the lookout for reviews.  Interesting.

Defiantly need some reviews on this when it is released.

Looks like it comes with a rear BUIS.  I wonder how well it works on handguns?

According to Leupold's website, the BUIS can be purchased separately.

I think that rear "BUIS" is optional and actually a handgun rear sight, as some of these are intended to be sold with a kit that fits them into the slide dovetail where the rear sight is normally located.  That would cause the handgun to lose its rear sight once the optic replaces it.

I doubt that optional iron sight would be of any value on an AR.   I want to get my hands on one of these and hope it shows up sometime soon.  No word from Leupold on actual release date.  They shouldn't tease us like this!  Especially not at Black Friday/Christmas shopping time.