When I saw this thread,, I KNEW there would be all kinds of responses.
Home or self defense has many variables. And as such, there are a LOT more people with their own idea of what is best. As an old saying goes,, "Everybody has an opinion."
Me included.
The OP has asked about (2) specific guns,, so we are good people who should respect HIS thought process as to which one would be best.
Yes, many people feel a revolver is not a good choice for SD,, yet a few facts come into play. Fewer things to operate or go wrong with a good DA vs a semi-auto. One thing seriously overlooked by many in this discussion is the potential of the necessity of operating it one handed. A DA revolver,, like what the OP is looking at, can easily be operated one handed with fewer potential issues than a semi-auto.
But I too have thread drifted.
Of the (2) guns listed,, I think both could be a good candidate. In a .357 revolver,, you have MANY different ammo choices,, and even more if you handload. A very big plus. You can also have a set of grips custom fit to your hands a lot easier.
But I have to agree with the quote, by cubrock; "GP100s are nigh on indestructible. They are hard to beat if a man wants just one revolver."
So, to answer the OP's question,, I'd prefer the GP-100.