You're asking which to carry, which ignores an obvious option: since both have major disadvantages, minimize your disadvantages and carry both.
I have long liked the 5-shot snubs for CCW. They are a size and shape that conceals quite well, the 5-shots make them quite thin (for a revolver) and perfect for IWB. They give flexibility to carry either good .38+P JHPs, heavy 158gr SWCHPs, or .357mag as needed. Revolver calibers like the .38spl and .357mag have some quite effective hollow point designs. However, lately, I have become uncomfortable with the low capacity.
I have an LCP. While the .380 is a pretty marginal round (so is .38, but it is better than .380 IMO), it can do the job with the right round and training. 7 rounds is definitely better capacity than 5 (though still not necessarily ideal).
So, my suggestion would be to carry the SP101 IWB or OWB (whichever you prefer) to get the advantage of the revolver rounds (and .357mag if that is your preference) and pocket carry the LCP to increase your capacity. Then you'll be carrying 12 rounds (much more comforting to me than either 5 or 7), 5 of which would be quite capable. If you don't like pocket carry, carry one of them on your belt and the other in an ankle holster, or do one strong side and one weak side. I haven't done this often, but (when in state where I can legally CCW) I have carried my 5-shot Taurus 85CH (.38+P) IWB and my LCP in my pocket.
If you don't want to carry both, I'd do what I actually did do and replace them both (without actually replacing them, just not using them for carry) and get a pocketable micro-9mm and a 6 shot (or better) revolver. The Taurus 617 is a 7-shot .357mag that is only slightly larger than an SP101 (it might even fit your existing holsters), a Rossi 461/462 is a 6-shot revolver about the size of the SP101 (and it will fit your SP101 holsters).