XDM 9mm over the XD9 or 40 for me..
I had a Glock 40 cal and never warmed up to it.. got the XDM 9mm and absolutly loved it.. (I also have a Sig 45 Equinox and love Sigs as well).. No more Glocks for me..
I'd get the XDM 9mm.. why pay about the same for an XD when the XDM is much improved over the XD..
Just my opinion.
I have the XDM 9 and love it.. shoots perfectly, take down and cleaning is very easy and quick, and there is never an issue with FTF's or anything.
the only negative is the grip size, i dont have a need for such a high capacity grip and wish they would make one a little shorter.. for carry purposes.
Great guns though so whatever you decide i'm sure you will be happy.