I currently own both Glocks and XD's. I really don't know if I'll be much help. I'm really back and forth myself as to which I like best.
My experience has been that ALL Glocks that I have had, from 9mm's to 10mm's, have been utterly reliable. Never had any trouble at all, and the finish is unbeatable. I don't really care for the trigger, but it really doesn't bother me either. I have complete confidence in any Glock, and even a simpleton like me can rebuild one if needed.
My experience with XD's is more limited. I am currently carrying my XD9 service as my CCW. The finish is all but worn off, but it has been close to 100%. The only malfunctions have been failures to go into battery. That was with FMJ ammo from a fully loaded mag. Only 2 or 3 times at the range. Never have had a failure to feed or eject. Most importantly to me is that I like the XD trigger better than the Glock's. The XD does have more muzzle flip, although not much, due to the slightly higher bore axis.
Having said all of this, I believe the Glock is the better of the two. The reasons being are the finish, the simplicity of repairing and utter reliability. I just don't have the same confidence in my XD's yet, but I still carry one. Thank goodness I don't have to choose to only have one or the other.