Seems to me a lot of gun store employees don't know what they're talking about. Around here the only thing they know about is 1911s and .40*&* Glocks. Whenever I mention 10mm, Sig, or anything not with the current trends, they look at me funny. TFL is by far the best resource I've ever found about handguns.
No matter if you pick a P228 or P229, you've picked an excellent pistol. I own a West German P228, and out of all the guns I've ever tried, it's by far my favorite. The P229 is nice, too... but when it came time to choose, I preferred the feel and balance of the P228. It's not "inferior" at all. If the P228 was an inferior weapon, I truly doubt the military and law enforcement demand for it would be so great.
Anyway, considering that they're both utterly reliable and accurate guns, just handle both of them and pick the one that feels best to you. Your really can't go wrong either way! Enjoy your Sig!