I have a set of XS Big Dot sights (the large dot) for the Shield.
There isn't a thing wrong with them. I just decided to go with some trijicons instead, for continuity with my full sized M&P Pro.
They were on the gun VERY briefly, but are in perfect shape, and required VERY little filing for my front dovetail. They won't go on my friend's shield without additional filing, so I am pretty sure they'll be just fine to install again.
To stand by my sale, if they're too loose for your gun, I WILL take a return on them! I can't if you file them further, of course.
They're in the original packaging, and everything that came with them is included (nylon punch, unopened red loc-tite, etc.)
I will ship them anywhere in the US for $70. They will even be shipped in the original XS shipping box, as I bought them directly from the manufacturer.
Please reply to this thread with interest, and we can set up PayPal in a PM.
Thanks for your interest!