I can't see any reason not to own one. I have gotten good use from mine, a stock GP100 with a 4" barrel no issues, other than some will have a rough and gritty trigger when new out of the box. Option one shoot the heck out of it and it will smooth up over time, Option two clean up the burrs and drop in a spring set.
The GP100 is on my short list. I don't own any revolvers but am getting my wife a 2" 38 for her conceal carry. Since she's getting a revolver, I decided to get a GP100 for myself and when I can find one, a Ruger Blackhawk convertible. For some reason, having a cylinder that can shoot 9mm intrigues me.
I own the Gp100 and the Security-Six. The Security-Six has well over 40000 rounds through it and still shoots five shot groups to 1" at 25 yards. There is no other revolver that is as strong or reliable.
I love my GP 100...I don't trek in the woods without it. I carry it in a custom leather chest holster (doesn't get caught in the heavy scrub). Built like a brick sh!thouse. It is a heavy bugger though...not for CC.
I have carried a Ruger Security-Six as a concealed carry weapon for 42 years. It has a six inch barrel, weighs just under three pounds (unloaded) and it has never been heavy. I started with a shoulder rig and then made a custom pancake holster for it when everyone kept telling me you couldn't carry the six inch in a pancake holster. You can too!
I even forgot I was wearing it once and went to the airport to pick up my sister-in-law.... It wasn't funny but I was told to place it in a locker and return. (long before 9/11/01)