I know this has been mentioned more than once, but please list the things that makes a 629-4 stronger than the old 29's. I saw one today that I am thinking about buying. It is not only a 629-4, but also a custom shop version with a heavy barrel with built in Weaver type base, magna port, heavy barrel with removable, hidden weights in the underlug. It is called 1 in 200 series. Pleas let me know your thoughts.