Any S&W Pro Series will have a slightly better trigger than normal factory production. Also, some of them have trigger and hammers that are forged instead of MIM along with trigger stops and easily replaceable front sights. Don't get me wrong, all of these are improvements over the normal factory line, but not necessarily enough to justify the cost.
The 627s are great, but my 2 cents is that if you're looking for 357 in Smith, try a 686 in the barrel length of your choosing.
Somebody had one for sale not too long ago on ingo, look back in the threads and see if you can find it. From what I remember, he was somewhere in the middle of the state.