With experience with ~20 Smiths over the years, I've not had any problems with the four that had IL's. While I fault S&W for buckling to the political pressure that led to the IL, I've found that after a month or two, that I no longer noticed it.
As an aside, the triggers on the lock models are as good in SA use as the previous models, but the DA mode is a bit heavier by a pound or two. Accuracy is indistinguishable between types. YMMv, Rod