I have experience with the GP/SP. No personal problem concealing the GP in the woods or during the winter but if you wore a T-shirt to the woods it'd be an issue. But coat, sweatshirt, heavy loose shirt, no issue for me with the Galco Summer Comfort IWB. Or the SR pancake if the shirt is longer. The GP has compact grips.
Always thought about the SP 4" to replace my SP 3"/GP 4" in one gun that could conceal under a T. But the lightness of the SP combined with the heavy DA trigger pull means that an SP will never replace my GP for home, woods, and even winter carry. The GP is just easier to shoot than an SP. However, the SP is very quick on the draw and point-able, which may make a bigger difference at 3yds or less.
I bought my stainless GP for $390 used out the door. Similar deals happen for the SP. I'm sure you can find the same for used older Rugers and Smiths and I'm sure they're fine too. The good thing about the GP/SP, however, is you can buy used knowing that it probably isn't worn out even if you don't know what to look for. Finally, a double action can do anything a single action can do (unless DOA). Practicality doesn't make the SA decision, but if that's what you want...