I have been looking at the 38 special +P airweight and the M&P 357 both have enclosed hammers,will the trigger pull be the same?Also will the Performance center be smother and lighter weight pull?
Trigger pull weight & smoothness is luck-of-the-draw - whether or not it's a PC gun, Pro-series or regular production. Depends on how well the parts fit and who put it together. Buying a PC gun is no guarantee of a good trigger.
I agree with Pizza Bob's assessment, I have several PC guns and a bunch that are standard S&W production, and the triggers are quite variable across-the-board with no correlation between where it was made and the quality (or lack thereof) of the trigger.
If I were to make one very general statement, I might say that DA trigger pull is a little bit better with the PC guns, but it's really subjective and the difference, if any, is modest.