My opinion... much like heavy .357's will loosen up a K-frame, and S&W's answer to this was the L-frame; a steady diet of heavy .41's (and likely .44's, but I don't have direct experience...) in an N-frame will do the same, that has been my experience. I don't think S&W has anywhere to go with the N-frame, unfortunately. Not that the S&W N-frame doesn't make a good pistol, but it has it's limits, and they are below what a Dan Wesson and some models of Ruger can take. Again, just my opinion.
As far as Ruger revolvers... I've had issues with EVERY Ruger revolver I've ever owned, starting with, believe it or not, a Single-Six... through a bevvy of .45 Colt Blackhawks, a beautiful .41 Bisley, and, finally, a .44SPC Flattop... all traced to either poorly machined cylinder throats, and/or torque bulges in the barrel, and in one instance, a poorly machined cylinder that rattled on an oversized Belt Mountain base pin it was so bad. I understand this is just my anecdotal tale, your mileage may vary, need not be present to win.