I own a model 66, 2 1/2", stainless version of the model 19 and a 4" and 6" model 28. The 66 is my ccw and is with me day to day, however if limited to only one gun the 6" 28 would be it. Digests anything you feed it, is inherently accurate and I doubt you could wear it out in a lifetime. Happily shoots magnums all day long.
If you buy the 28, I don't think you'll be sorry.
As far as nickel goes never owned one so I'll have to defer to more knowledgable folk.