This is good advice, which is another way of saying I strongly agree with it. IMO, a 4" K-frame is about perfect, but RB may be much better than SB for you. However, you need to try your SB with better (smaller) grips before abandoning it. Years ago, I would have recommended service (not Magna) grips and a Tyler, but that may not be practical this week, or maybe even next year. Rogers/Safariland grips (plastic) are also very good for those for whom K-squares are marginal. You might even try Pachmayr Presentations (small). If all else fails, go to RB, but you'll still have to get the right grips. Pachmayr Compac or (more likely) Pachmayr Compac Pro are very likely to work out for you.
This is where it is to your advantage to visit a brick-and-mortar gun store, sometimes referred to on this forum as a LGS, where you can try a pair of grips to see how they feel. It only takes one wasted internet purchase to wipe out any advantage of shopping thus, rather than visiting your local gun store.
Good luck!