Yeah I wasn't really thinking about taking a picture...wish I had now! The price was $600 which is slightly less than what the 4.5" costs usually(wanting to say I paid $630 for mine, but I've seen them for $575).
I'm pretty sure the backstrap is interchangeable though because that's one of the "m factors" I would think! I'd go ahead and get one in 9 but I really don't want another pistol caliber...I have a hard enough time keeping .40s and .45s on hand...dang I need to start reloading!
I've been considering a m&p compact(I like the thumb safety on some models...wasn't sure but I like the idea), but I'm already familiar with the ergonomics and what not of the xdm so it wouldn't be so much like shooting a completely different gun when at the range and what not. And especially in a carry scenario I think we can all agree that familiarity with your chosen carry weapon is key