For me, having shot my GP with both the Hogue grips and the older style with inserts. I have found that my accuracy is much improved with the Hogue grips, the finger grooves really do fit my hand well.
Glad to hear from other GP100 owners. I used mine (6" SS .357) with the factory-supplied Hogue grips for a few months, and I liked them well enough.
I recently decided I like the wood-look better and got some that closely duplicate the Hogues, but are a bit fatter, and fit my hand better. Made by Hogue, too. Also, I like the smooth feel of the wood---more comfortable after a couple hundred rounds. Since I shoot mostly .38s, recoil isn't an issue. The ones I chose ran about $75 but, considering how much I spend on gun stuff, not a bad deal.
Sorry I can't send a pic. Mine are coca-bolo (coco-bola?), item # 80300.
My 4" GP100 stainless came with the original rubber handgrips with rosewood panel inserts. I like them much more (aesthetically) than the new Hogue grips. And they still do a great job dampening the recoil. But they looked a little dull. I rubbed in several coats of tung oil, using 000 steel wool between each coat dried. Looks like a new gun.
Personally I like the houge grips on my 4-inch SS GP, they seem more rugged and hardy, and overall give me the best control over the firearm. That being said now that I look at the picture of the original grips w/ black-laminate wood inserts on the Ruger web-site they would be a lot more aesthetically pleasing. Maybe Ruger ought to introduce a houge mono-grip with black-laminate wood inserts for the GP