I'd recommend a Glock over an XD. I had a full size 5" XD .45, but even after over 1000 rounds I could never get use to how "squishy" the trigger was. At 7 yards I had a hard time keeping my hits on paper. I don't own a Glock, but the ones I've shot have a much nicer trigger then my XD.
Really, the best general advice you can get would be to rent or borrow a Glock, an XD, a Sig, a HK, and whatever else you might want to buy and take them out to the range and buy the one that you shoot the best.
Really, the best general advice you can get would be to rent or borrow a Glock, an XD, a Sig, a HK, and whatever else you might want to buy and take them out to the range and buy the one that you shoot the best.