I bought an XDM 5.25 in 45 for almost the exact same reason. I needed a 45 for pin shoots that started happening locally. I'm primarily a Glock guy so I looked at the Glock 21 but couldn't find one at my local GSSF shop and I found the idea of paying full retail for a Glock unappealing. Eventually I drifted to the 5.25 because it has a few competition features on it from the start. I like it quite a bit but I've only had it about a week so I've only shot 200 round so far so not exactly a lot of experience with it but I'll give you my impression.
The trigger is smooth and breaks pretty clean and the reset is audible but a bit longer than I'm used to with the Glock, not necessarily long, just longer than I'm currently used to. The trigger is not completely dead after you drop the striker, so dry fry is going to be very easy.
Came form the factory with the smallest backstrap on it and it actually feels like a good size. With the small one the back is very straight, not much of a hump. It didn't feel that large until I went from the XDm to the Glock 17 and then the Glock felt small. The grip itself is a bit smoother than even a Glock, I've invested in some of the grip tape for it.
The magazine release works from both sides which I love because I use my index finger on my strong hand to depress the release. I got an extended mag release which makes it even easier. The interesting thing is that it not only moves laterally it also rotates. Looking at the mechanism it makes sense why, it's the way they made it ambi, there's this little paddle thing inside the magwell that pushes out of the way. It's hard to describe. Not really any advantage or disadvantage just kind of neat.
The sights are very nice. The front sight is a big wider than I'd probably like but I don't think it bothers me enough to go through the trouble of changing it... at least not yet. The rear right is fantastic. Fully adjustable, with a flat black serrated rear blade is my preferred setup though so your mileage might vary.
I thought I would hate it but the grip safety isn't as bad as I thought. I have never once noticed it was even there which is probably the kindest thing I can say about it. You can get a larger one though if you are concerned. It made me change the way I show clear vs how I show clear with my Glock but the addition of the front serrations on the slide made it easy.
The muzzle flip wasn't as bad as I thought it would be for a 45. It's definitely more than a 9mm Glock 17 but it's not wild or uncontrollable by any stretch.
So I bought it just to use in pin matches and now I'm thinking about running it in some IDPA matches in CDP. I wish you lived closer I'd tell you to bring a box of 45 and give mine a go.