Galco "king tuck"
Yes, I know it's large and can be a pain the first few times you try to put it on.
But after a day or two you actually forget it's there, and it's become my all time favorite IWB carry (and I currently have more than 20 IWB holsters).
I use mine for the XDs and it is virtually undetectable with any normal outfit I wear (and here in Florida, that means light clothing!).
BUT...and this is what I love MOST about the XDs...you don't even NEED a holster! The slab-shape that only a mother could love (at first) and thin cross-section means that it just fits and sits comfortably in every pair of casual pants and shorts that I own (it IS a bit of a problem with softer, thinner, dress pants).
My Kimber Ultra-Covert II is no longer my "daily carry".