+1 on the extra lube during break-in on the XD-S. I bought one recently and had a ton of light primer strikes on the first 100 rounds. You'll find a 20 page forum thread about the issue at XD Talk. I called Springfield, and they said it needed a "death grip" and to be very wet during break-in. I already hang on tight to avoid limp wristing on small barrel guns, since they need all the help they can get to cycle correctly - so I took their advice and oiled it every 30 rounds during the next 200 rounds or so, and didn't have a single light primer strike. It's almost broke in.....
EDCs: HK P2000SK .40, Ed Brown Kobra Carry 1911
BUGs: Sig Sauer P938, Ruger LCP
Former LEO and USAF Security Forces