When you compare a S&W, a Colt Lawman, and a Colt Detective Special you're comparing three totally different "feels".
The S&W and Lawman are "similar" in feel since neither "stack" or get heavier as the trigger is pulled. The big difference between comparable S&W mid-frame revolvers and the Lawman is, the Lawman has a coil spring action, and the S&W uses a leaf spring action.
These do have a different feel, but neither stack.
If you compare a small frame, coil spring action S&W to the coil spring Lawman, I give the edge to the Colt.
Like all of the old Colt actions, the DS does stack. As the trigger is pulled, the tension gets progressively harder, BUT the Colt is famously smooth.
All this comes down to a matter of preference. Some people just prefer one or the other.
Today, many people who try an older Colt revolver complain about the "terrible trigger" pull. This is usually because they've never experienced anything but designs that do not tend to stack and the older Colt's have a radically different feel.
Among older shooters who used both S&W and Colt revolvers, it comes down to simple preference. Some people like the straight through pull of the S&W and most modern designs, and some like the Colt action since you can "stage" the trigger for a smooth let-off.
Bottom line is, it comes down to personal preference of what each feels like to you.
A bigger consideration is in smoothness of action, and accuracy.
The Colt DS is famous for being the most accurate of all small frame revolvers with a smooth action and a six shot cylinder.
The small frame S&W's are not as accurate, have a coil spring action that is difficult to get as smooth as the Colt, and have a 5 shot cylinder. In addition, some people find the small S&W's TOO small to offer a good shooting grip, while the Colt DS is about perfect in size.
The Lawman is a bigger gun, more comparable to a S&W 686. The Lawman is a tank, and possibly the strongest snub revolver ever built.
Another consideration is holsters and accessories.
Anything made for revolvers is offered for S&W. You will have no trouble finding a huge selection of grips and holsters.
Grips and holsters for the Colt DS are also plentiful, but not as much so as the S&W.
There are few holsters and grips offered for the Colt Lawman.
Best suggestion: Try examples of each to see which "feels Right" to you.