I've only read the posts on page one and this one. So far I've missed seeing one of the main reasons the XD/XDm has grip safety in the first place and that's to keep the pistol from going out of battery when holstered and then drawing with an out of battery pistol. It's also there to prevent what's referred to as "Glock Leg". Since you're not engaging the grip safety when you holster, there's no chance for the trigger to get caught on something and discharge.
As far as the LE market, Glock sells to police departments at near giveaway prices. They do that for the market value it has with civilian shooters who want to carry what the police do. Since Springfield Armory is an importer for HS Produkt, they simply don't have the margins to compete in the LE market and they don't even try, but you will find departments that have XD/XDm pistols on their approved list.
I have the XDm 4.5 in .45 ACP and consider it superior to the other polymer framed pistols I've ever considered buying like the G21, FN FNP-USG, M&P, and H&K USP. I didn't consider the HK 45 because of its nearly $1000 price tag. It is simply too expensive for a polymer framed pistol.
The design of the XDm's trigger allows it to be easily enhanced with a PRP or Springer trigger kit. Mine has the best trigger I've ever had on a service pistol and you can completely eliminate overtravel. Something not easily done with the competitiors. They can all be enhanced but to my knowledge, the M&P and Glock being more similar to a DAO trigger don't allow for an overtravel provision. The H&K can, but try to find someone that does a good job improving the trigger and consider the price paid for the pistol with a trigger job and the XDm comes out smelling like a rose.
I shoot as many cast lead SWCs as I do JHPs. The XDm has a "Match Grade" barrel with conventional rifling. Much better for shooting lead than a polygonal bore and my XDm is extremely accurate.