I have zero experience with the XD.
I have watched a Miculek you tube vid comparing S+W M+P,Glock,and XD.
What I noticed about the XD was the slide is carried by a single steel block pinned in the polymer frame,and it is not very long,maybe 1 1/2 in or less?I never measured one.I could be wrong,but the for and aft blocks of Glock or M+P look,IMO,more robust.But that is a seat of the pants opinion.
As I recall,when I spoke with Mr Clark,his spring recommendation for this 1911 was about 24 lbs.Think slide hammer.
If you want one,build it,and do it your way!!I'm not trying to talk you out of anything.It has been done,it can be done,and it works!!
I'm just giving you some things to consider up front.
I saw a Hickok 45 youtube where he is shooting a 10 mm double stack Glock with a Lone Wolf barrel.This barrel is conventional,vs polygonal,so hard cast bullets work.He was shooting 200 gr Buffalo bores,I think,at 1200fps or so.
HMMM.Would I rather have a single stack .460,flinging 250 gr bullets at 1300 fps,or a 15 or so round 10mm double stack mag with 200 gr hardcast at 1200?
Pretty good question.
But I already have a SuperBlackhawk and a few 45ACP1911's.For myself,I can't justify the $