You've gotta love them both for their own qualities...
The 629-1 is exactly like the no-dash model except it no longer has a pinned barrel or recessed cylinder. If it remains original it will have the classic lines of earlier N frame guns with wood target stocks. Beautiful guns!
The 629-6 is the latest version. It may or may not be a model with a full underlug barrel. Several variations exist. It possesses the new cast parts (MIM) and a internal locking system so it can be disabled for safety purposes. The later dash number guns have all the longevity upgrades that increase its durability. The dash 6 benefits from the lifetime S&W warranty.
Both have their supporters and their detractors. Some see changes as necessary and beneficial, others see changes as diminished quality creating an inferior product.
I own both, shoot them both, and love them both for their contribution to the S&W lineup. All things being equal, If I were a new shooter I'd probably opt for the gun with the outstanding warranty. As a collector of earlier S&W handguns I'd likely look toward the dash 1.
A difficult but pleasant decision to be making....
