The Coonan is still an absolutely great pistol.
Hey, the 357 Sig should be a good round, it just works best with lightweight bullets.
The main weakness for me is reloading the bottlenecked case; the price of factory ammo seems to be getting better as well.
The main advantage should be the similarity to the 125gr Maggie performance and the number of rounds available IF you have standard capacity mags. With ten round mags, the new 7 and 8 shot S&W revolvers look pretty good for those who appreciate them. Revolvers can reload as fast as the vast majority of autos, most folks just do not spend the short time it takes to develop this skill.
The Glock 10mm's, with the original standard capacity mags, are a very good idea. But then I think the same about all the Glocks.
The .357 Magnum round is still a very good ctg., that much hasn't changed and never will. Revolvers still do many things well. The bottom line is that I don't want to be looking at the business end of a .357 in the hands of a determined man or woman.
Another good auto round to look at is the 9X23. Check out Dane Burns' website on this.