Yep, +1 on the Hogues. I shot some .357s out of my SP with the stock grip, and went out and bought the Hogue the next day. So when I got my GP, I bought the Hogue right away (as you may know, the Hogue is the stock grip on the GP nowadays).
If you're still deciding between the SP & the GP, the SP is easier to to conceal, and lighter. Most people feel the GP is a little too heavy and bulky for concealed carry. I was in this camp, and have carried an SP101 the last few years, until a couple weeks ago I made myself a holster along the lines of the Kholster and the Crossbreed, and found I can conceal my 3" GP100 just fine.
Anyway either one's a great gun.