I've owned 5 or 6 Mark III's. One .357 and the rest .22's.
Seems strange that they were Colt's "economy" gun, of the time. One summer when I had a 6 inch blue, I was buying a 500 round brick of ammo every weekend. I was shooting the entire brick up on a farm, mostly plinking. I've always had the knack for ariel shooting, and was shooting cans in the air, etc. After the first few weeks, I was shooting double action only. That fall I bought a Marlin 39-A lever action rifle. It was almost too easy, after all that pistol work.
Any way, the Trooper III with a lighter trigger spring, a modified hammer spring, and an action polish, is hard to beat.
The Trooper 5 has an even better trigger.
After years of other .22's, I found a new Mark III, 4 inch and I'm having a ball shooting it.