A Glock feels like a heavy, but crisp single action pull. The XD feels more like a very smooth light double action trigger pull. Which is odd because the XD is a true single action while the Glock is classified as double action only.
I suppose it is what you are used to but I shoot the Glock trigger much better. The trigger breaks at 5.5 lbs and is extremely consistent from shot to shot and with every Glock I've shot felt exactly the same. You can buy Glocks with 3.5 or 8 lb triggers if you wish, but I shoot the standard 5.5 lb. trigger best. I can put about 4 lbs of pressure on the trigger, make any final sight adjustments and then give it that last 1.5 lbs of pull for very accurate fire. With the XD's I've owned and shot I could never figure out exactly when the trigger would break.