Two years ago, my '02 5" JM PC 627 V-Comp met my new 4" 627 Pro. Sadly, the older revolver started growing cobwebs - but that's due to me and my mature eyes. The dovetailed Patridge sight on the older PC 627 was not supported, even by the PC Shop, with replacement choices - especially my new found friend - a fiber optic, ie, HiViz sight. My 'mature' eyes need the help. The 627 Pro, like my other 'Pro' series revolver - my 625JM - takes a spring-loaded sight - changed by hand in seconds.
I know you wanted to compare PC Shop revolvers, but the 4" 627 Pro is really similar - certainly a finer 'production' revolver, if not quite a PC Shop piece. The V-Comp is heavier - especially 'out front' - with that heavier and longer shroud, not to mention the Comp or cover. With some of my trigger work - and lighter Wolff springs, it is not bad at all. It came with a modicum of a trigger job. It is, however, now married to Federal primers for 100% reliability. The V-Comp is smoother and maybe lighter - and pops anyone's primers. Yeah, the PC Shop guys are a lot better 'smiths than I'll ever be!
If you want to shoot bullseye - and the Patridge sight is for you - get the V-Comp. If you want a faster grab with any type of sight change done in seconds - and want to save some money - consider the current 627 Pro.
Stainz
PS If you were near C.A. (Central Alabama), I'd show you my JM V-Comp - it may be for sale. Italy is a bit far! I did live there - '72 - La Madelina (USN).