The slab sided barrel and tapered lug of a 627 Pro (41.2 oz) pare a whole 0.8 oz off the regular 4" 627 (42.0 oz). The 627 Pro, SKU # 178014, has an MSRP that is $56 over the production 4"-er the OP mentioned - and a bargain with it's precision barrel & crown, spring loaded front sight for fast tool-less changes, moonclip ready & eased charge holes, and a modicum of a trigger job. Below is mine along with my 5" h-l 686+ for comparison.
My 5" JM PC627 V-Comp and the 5" h-l 686+ pictured above have cobwebs these days. The 4" 627 has been my favorite since it came home with me 5/08. It soon got the HiViz front sight and Ahrends 'Retro Targets' in cocobolo. It rivals my 4" 617 for staying nasty from so much shooting!
Stainz
PS Ranch Products has the moonclips at $50/50 or $75/100 shipped. Starline .357M brass nearly jumps into the notches.