I also have a 2¼" SP101. It's a nice gun, but I don't carry it at all.
Please note: these are only my opinions! As always, YMMV!!
At 25 ozs unloaded, I think it is too heavy for pocket carry. Put this gun in a pocket without an equal amount of weight on the other side & pretty soon your jacket will be listing waaaaay to 1 side. I'm not sure what 5 rounds of .357MAG weigh, but at 1.4 ozs each you'd have 2lbs to equal out.
For OWB belt carry it would be fine. I usually go IWB when I belt carry & therefore employ a flat semi-auto.
Now the advantage to the weight is when you are touching a round off! While it does recoil, that extra 13 ozs or so it has over the super lightweight S&W & Taurus guns will not shock your wrist & pound your hand as badly. I would think that the 3.06" barrel would even be milder. While it is true that 13/16" isn't much, it is over 36% longer. Maybe someone here has fired both & can advise?
At least in my example, the trigger pull is a lot heavier & not as smooth as the 637 I recently picked up for my daughter. Not even close. I bought the SP101 used. I haven't shot it too much, but it definetly has more rounds through it than a NIB.
To your question: if I was to use an SP101 for carry it would be the shorter barrel & only belt carry. I use mine for an HD gun, but if a used 3" would have been in the same case when I bought this one, I'd have gone for it instead. I'd expect it to be a nicer shooting gun.
But with either one, I'm sure you'll enjoy your purchase!