I'll stick pretty much to the question at hand and go against the grain and call a tie completely dependant on what you want to use them for. Neither is a piece of art and neither will be an heirloom but IME they both go bang. If you compare the 3 3/4" barreled RR's up against the HP, accuracy is about equal and neither is easy to shoot well. For my uses the HP wins. Both are plinkers and the HP is more fun for close range can destruction. BTW, loading single actions .22 revolvers can be tedious. Probably the main reason the HP would win the fun category. Being said, neither is a bargain. Maybe they were when you could buy either new for $110 but now that they've approached $175-$200 I wouldn't touch either with a 10 foot pole. As for the RR being able to fire .22M's? I believe the .22M is possibly the most pointless handgun cartridge ever. Toss the .22M cylinder in a drawer and forget you have it.
OK, I lied. I'm not gonna stick to just the guns the OP asked about. I'm not gonna sit here and tell you to wait for a bargain that may never come but you can get better guns for very little, if any, extra money. I see new 22/45's at the shows for $250, used will be less. Browning are a little more new but not on the used market. Used Bersa's should be down in the low $200's. Heck, I'd probably sell mine in that range. Used H&R's are well below $200 and better guns than either the OP asked about. Neos and 22A's? Blah, not for me. Mosquitoes are flaky and over priced, same for the Walthers.
