Well, the round butts are slightly easier to conceal, and IMHO is the way to go because there are a plethora of companies that make grips to fit it with the square butt external profile. Just gives a little more flexibility.
As far as NY-1 triggers go, I believe they are DA only, and in the 12# neighborhood. If the price is right, you will likely need to replace all of the springs anyway.
If your are interested in a decent S&W revolver, may I suggest a model 65, same features as the 64 except the ability to shoot .357 too, but either are fine guns.
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