The 659 is on the verge of becoming a collector piece.
These guns were only made for a short period of time.
Be careful if you muck with the innards, that you don't alter something such that you cannot restore it to "correct" configuration. Unlike the Browning Hi-Power, there is no significant improvement to the trigger-pull by removing the S&W magazine-disconnect feature.
Unless you REALLY think you will run into a situation where you only have one bullet, and you are missing the magazine, and your life is on the line, there is just no point in removing it.
...except if you are just so profoundly philosophically-opposed to the thing, that you can't bear to look at it, knowing it has that feature.
If you really want to start taking things apart, I recommend that you start with the firing pin. Every used S&W semi-auto that I've run across has a firing pin that looks like this, or worse.
I am philosophically opposed to magazine-disconnect features.
For serious defensive carry, I would not choose to carry a gun with that feature.
I'll admit to carrying a Glock 22 for defensive purposes.
But the Glock is Butt-Ugly.
Always has been,... always will.
Pretty guns are the ones you show to your friends.
Ugly guns are the ones you show to your enemies.
The 659 has a look that will turn heads for many years to come.