It depends on how you intend to carry. Most of the “pencil-barreled” Colt’s (which I also prefer) have the full-sized frame rather then the “short-butt.” I find them to work fine in a holster, but be to big for pocket carry. When going to a holster I almost always choose an all-steel gun. The additional weight makes them easier to shoot accurately, and refinishing presents much fewer problems. They also wear better because the aluminum Cobra is softer.
The only advantage the (aluminum) Cobra has over the (steel) Detective Special is weight, and the difference isn’t all that much.
How tight and well timed either model may be depends on how much they were used, and how. On the used market you find them in all sorts of conditions, but be aware that the like-new ones are becoming very expensive. What you want to look for is one in perfect mechanical condition, but with a little finish wear. You sometimes find examples that were carried, but never fired!
Jim March posted a checklist at the beginning of The High Road’s revolver sub-forum that explains how to check out used revolvers, and it applies to Colt’s in particular. Read it and learn some good tips.
As a general rule of thumb I consider the workmanship in the older guns is better then the latest production. It all came down to labor costs, and how many guns an assembler was supposed to build within a given time frame. They were all individually hand fitted.
In terms of recoil, I don’t find a great difference between the Cobra and Detective Special because both have relatively large handles which give good support within the hand. S&W J-frames are another matter.
Smith & Wesson’s line of J-frame snubbies is smaller, but only hold five rounds. The only substantial advantage I see in them is when one pocket carries.
