I'm one of the SP22 owners here. Which model do you have? I have a mod 3 and I installed the slim grip. I also have the red dot sight (save your money and get a better one) the weight set, which I haven't felt the need to install, and six mags. The internals have a lot of pressed and welded steel but the gun runs well in spite of its looks. Outside it's all Logan's Run (if you're too young to remember it, go rent the DVD or stream it from NetFlix).
Right now I'm playing with a new P22Q and my regular target .22 is a Ruger MKIII but I still pull the SP22 out now and again for a range trip. Plus, when I get my can it will attach to the P22 AND the SP22!