The Pro Series guns are factory manufactured with upgraded parts, supposedly under the supervision of the Performance Center. The Performance Center guns are usually considered a little more high end. I have a 627 Pro that I really like, but I just think of it as a factory upgraded gun.
Performance Center firearms are manufactured in the PC from frame to finish. It is done on their mills with tooling that is replaced more frequently than what is done in a production environment. Even though model numbers may be the same PC Vs.Production, milling specification might not be. PC firearms have many features not on production guns. This makes them expensive.
The idea behind the PRO series was to offer some of the PCs innovations without the full PC cost.
So frames produced on the production floor get a feature or two or more that were previously only available on a PC firearm. The PRO series is a blending of Production and Performance Center
Personally I believe that the Performance Center offering are worth every penny.
I do own several of the Pro series as well. Mostly because of their configuration. The Model 60 Pro is a great little kit gun. The 640 pro is a wonderful pocket pistol and so on.
I have a few Pro series: 60 Pro, 625JM, 627 Pro, & 632 Pro. All were bought new - and delivered perfect, save the 625JM's sharp edged grooves on the trigger's face - easily eased with a strip of emery cloth. My two 2 5/8" PC627 UDR's, also bought new and from the 2010 production, each came with poorly fitting Eagle boot grips and their front sights were way off - all the way to the left of the dovetails (For shooting around corners??). They functioned great - but no S&W should be sent out the door like these, much less a well hyped PC product. For my money, if the Pro Series makes what you want, why spend the extra moola?
To defend the PC guns - I centered the sights and both guns were within 1-2 clicks of 'on' - and S&W did get me a later set of Eagle boots that fit - then I found other better fitting PC shop grips.
The idea behind the PRO series was to offer some of the PCs innovations without the full PC cost.
So frames produced on the production floor get a feature or two or more that were previously only available on a PC firearm. The PRO series is a blending of Production and Performance Center.
Can you tell me what those features may be? I recently purchased a 627 Pro and honestly don't know exactly how it differs from a production gun.