I had a 4" SP101 in 327 Federal. I had the barrel cut to 3", and sold my fixed sight 3". I still regularly carry it, but it's not perfect. Even a good SP101 trigger is at best a bad GP100 trigger. The Altamont grips are very small, and the grip angle is bizarre. The Pachmayer grips are a little more comfortable, but again the grip angle is horrible, I almost have to full lock my wrist down to shoot them. I had a custom wood set of grips made to my hand and specs, which they did, but there's just not enough room in the SP101 grip stud for one of my fingers behind the trigger guard. It's really uncomfortable to shoot. The grip I've settled on is the Hogue rubber. It's a tiny little grip, but the angle is actually correct, and it's not uncomfortable to shoot at all. It's not a good grip for hunting or ultimate accuracy, but it is pretty good for concealed carry.
My advice is if you want a Ruger in 357 magnum, get either the LCR or a GP100. If they made an LCRX 3" in 327 Federal, I'd sell my SP101 tomorrow. The LCR is simply a better small gun, and despite being even smaller and lighter than the SP101, has a better grip stud design, and better grips offered for it. The GP100 is all around a WAY better shooter for fun or for hunting. I'm really hoping this Henry can be what the SP101 should be.