I think you mean the Night Guard? I have one in 44 magnum (model 329) but it was unreliable right out of the box. The factory fixed it (longer firing pin) but it took 7 weeks. S&W may have released that line a bit too early - many new owners complained about FTF issues which is terrible in a new gun marketed specifically as a self-defense gun. S&W made it right, and they have a lifetime guarantee including shipping both ways, but I'm not a big fan of the NG series because of my experience. YMMV.
Now the Performance Center guns - different story. So far no issues.
I like 357 magnum. My first ever gun was a Ruger Security Six in 6 inch, and it withstood my introduction to reloading and many years of shooting. I foolishly traded it for a 4 inch and then foolishly sold the 4 inch to a family member. I have never sold another gun in over 30 years (and hope I never have to). I buy guns, I don't sell guns.
Bought a S&W model 66 and I still have it. A stainless .357 magnum in 2 1/2 inch. Nice small powerful gun. I had a gunsmith do the action and trigger. There's nothing like a good S&W trigger (in my opinion).
And now the R8.
.357 magnum is nice in that you can shoot so many different loads in both 38 special and .357 magnum. You can start a new shooter on 38 special wadcutters, then move them to a heavier bullet in 38 special, then +P, then if they're ready you can move to a light .357 magnum. And eventually go all the way to a heavy 180 grain .357 magnum at 1300 fps. All in the same gun. I like that.