Do you like the Colt OMM or the Diamondback the best. I know that the OMM has the Python lockwork where the Diamondback has the Detective Special lockwork. It seems to me that the OMM is much better. Give me you input.
I'm not sure anyone can answer which is best. But I do agree in part with Majic, that for target work the Officers Model Target gets my nod.
You are correct that the lockwork on the Officers Model Target and Python is the same. And it is a heavier frame than the Diamondback. You are also right that the Diamondback and the Detective Special are based on the same frame size, the D-frame.
As far as which is better it may be a matter of personal preference. Although the Diamondback frame is smaller, some will like the balance of the heavier full underlug 6" barrel better than the OM in 6".
Hand size or grip size never made any difference to me between the two subject guns.
Don't forget the fixed sighted models,such as the Official Police .22,usually in 6" and rarely in 4".While sought by collectors,the under 90% finish examples aren't that pricey. I also own a 3" Cobra .22,a nice small .22,that IS a collectible(but I shoot it!). Here is an example of Colt's failure to appeal to the market; price was the same as the S&W Kit Guns(M-34,43 & 51)that came with adjustable sights,and the M-51 was in .22 magnum. The only advantage the Cobra had as a rough & tumble trail gun,was that its fixed sights wouldn't be damaged in a fall! But I find J frame Smiths too small for my hand,so I sold/swapped all of mine. Probably my favorite .22 Colt is an early(Pre J Frame MK.III) Trooper with the 4" bbl. Not many were made,and it is very "handy" Officers Model",but with the shorter Bull barrel. I had a lousy experience with a .22 Mk.III Trooper,as explained in my post under the Lawman vs. Trooper thread! Bud