Re: XD45 Tactical
Lots of people put that grip tape, or the grip decals on their grips so that they're that texture on the middle of the grip. All of the XD's have the texture on the front and backstrap. When I first got my XD-45 Tactical, it wasn't easy to rack and was pretty stiff. My slide stop was VERY VERY stiff, but it got a bit more loose as I broke it in. Now it's not hard to use at all, and feels great.
There is something that the XD's do that alot of people aren't familiar with. You CANNOT rack the slide back unless the grip safety is depressed. It's supposedly a feature that they made to keep the pistol from going out of battery when you holster it. If you're holding the pistol in a different way from how you would shooting it; not holding the grip safety, you'll have HELL trying to rack the slide and still won't get it done (or will break something). This might be what is happening to you and when you shift the grip to push harder, you may be depressing the safety and getting it to go back. It could just be stiff like mine was when I first got it, but it could also be that you're not holding down the grip safety. Hope that helps.