I have an XD45 Compact (4" Barrel w/ the shortened grip), and I'm planning on getting a Crossbreed SuperTuck when I start carrying at the end of the month (waiting on my license).
I currently have a Blackhawk! Sportster paddle holster (got mine for $30 at Bass Pro) for open carry, and I love it. I haven't found it uncomfortable in the least--whether I'm in the car, walking, or sitting in my office chair--and it's very easy to draw from. The obvious problem is that it sticks out from your body more than an IWB holster like the Crossbreed, so it's not great for concealment unless you have a decently heavy coat to put over it.