This stuff is subjective. What works for me won't necessarily work for you.
I've tried nearly all the available grips for the SP101, and actually like the stock Santoprene grips best (with custom inserts, of course).
The Uncle Mike's, Pachmayr, Hogue (worst of all!), Badger and others all change the natural pointing characteristics of the SP101 for me, making it no longer reliably match natural "point" to point of impact, and all aftermarket grips also raise the barrel axis relative to the hand, at least somewhat, compared to the stock grips.
Unfortunately, the new management at Ruger (since Wm. Ruger Sr's death) has stopped offering the original grips in favor of a rubber Hogue abomination, so if you find the original grips more to your liking, check eBay or do a web search for spares.