not an XD, but i have a friend (really, i do!) who put an APEX comp trigger kit in his M&P. It's amazing but he's thinking of taking it out and swapping it for the duty kit, it's so light as to be nervous making for IDPA style shooting
Done my own PRP trigger. Big difference. Just pay close attention to what you are doing and you will be fine. I say close attention. Removed a pin punch to quick and lost the sear spring. Heard it rattle around a few times. Still M.I.A. lol
My xd 40 tactical trigger was done by Jeremy at Springfield Armory, incredible. If ur in Ohio during the National Matches at Camp Perry they will do them there, or in thier custom shop at the factory (you could send it in).