Duvall Dean: I also busted my ribs up 2 yrs ago. Bought the 616 and love it. Won't ride without. Dropped into a gully last year in poor vis and thought I knew where the bottom was. Pinned it about 10 feet to soon and was fully pulled back when I hit the bottom. Bounced off the bars with my chest hard enough to get bucked off. Didn't feel a thing couldn't believe it. Whichever you go with I think there a must. I wear my beacon on the outside of vest so it won't point load my sternum.