Ruger can handle using heavier loads longer at the weight cost mentioned.
But since OTS 240 gr .44 mag HP ammo will do all you need, and the 629 can handle realistic limited use of powerhouse loads if you get the urge, I'd go with the 629 for weight, looks, and I like the grip and cylinder release better (if you have any other Smith/Taurus/Charter revos the cylinder release is the same motion, Ruger is a "push-in" button, so "training reason" too).
-But-, I'd go 5" because I think the gun looks better proportioned that way and, hey, 50 fps more or so.
I like the 3" K and L frames for the same aesthetic reason (that, and the full length ejector rod).