I have both, and love both. I will say the XDS is a tad heavier by about 1.5 oz if that matters to you. I am however capable of concealing the XDS 45 (same as the 9mm) better than my shield. I would say whatever you like better its a wash. get what fits your hand.
my personal opinion is, XDS in 45 and Shield in 9mm. So if you want a 9, then its the shield. If you want a 45, then its XDS over the shield.
