Yeah about 5 to 6 years. The only update has been the cover screws being changed which was the major fault with the design. Older flex heads can be updated to the newer style. As for anything eles, if you look at the old 36, 95% of changes made over the years was just appearance. Some will say newer 36 tooths are stronger then 20 year old modles, but it is more to get guys to buy ratchets every 4 to 5 years. The only reson to maybe hold off is SO is just releasing 80 quick release versons, first time I have ever seen those with comfort grip. Does this mean flex head modles of those are coming, I don't know. So if quick release ratchets excite you, maybe hold off, but otherwise, just get some.