I also...
...own both. Although both share the same frame, that's about it as far as comparability goes. They both serve two different purposes.
My 625 JM fits the picture of a "combat revolver". .45 ACP, round butt, front combat sights, etc. It's a really fun gun to shoot at the range. It has superb balance, lacking only (for me) in the realm of the stocks. The JM style stocks are like holding a baseball bat at the large end. Other than the stocks, though, I love the revolver. The solution for me was to use a set of 1980's Morado S&W combat stocks. I have two sets, one on my Model 29-4, and one on a Model 24-3 Lew Horton.
On the other hand, my 22-4 is a different bird althogether. It's profile harkens back to the age of carrying a fixed sight, large caliber revolver as an open-carry sidearm. However, for a different reason, the standard stocks are horrible. They are too small, and I end up over-gripping the revolver. I tried an older set of Herrett's Shooting Masters, and they worked a good deal better. I also tried a set of Altamont-made S&W rosewood service stocks, and they were somewhat better. Right now, I'm waiting on a set of Ahrend's to see if I like them better. The 22-4 has very manageable recoil, and I sometimes carry it as a concealed revolver in a Galco suede-lined holster. I know it's a bit large, but there's something about that nice N frame that I really like.
I thought once about trading in the JM on something else, but I just can't see letting such a great revolver go. There's just something about those shorter barrel N frames. I glad I didn't have to make a choice between the two.
PS - I also have a Model 21-4 (not a Thunder Ranch) that came with a set of Ahrend's combat stocks. It's also a really sweet shooter.