This chesty replaces my Vaughn 7450 which was good, but since I started facing recently retired AHL/FHL/NCAA-D1 players the 7450 protection broke down quickly. The two chesty's are constructed almost identical, but their are major differences that I will outline.
7450 has 2 layers of protection, The 7600 has 4 layers of protection and 1 layer is removable so you could make it 3 layers if you choose. The 4th layer is Velcro-ed on the inside of the outer shoulder pad.
7450 has 2 layers, 7600 has 3 layers
7450 does not have wing flaps that protect on the inside of the arm high in the rib cage area. The 7600 has removable flaps that protect in this area. (they are Velcro-ed on).
I am 5'10", 180lbs, arm span of 71" and the 7450 fit me very roomy/on the larger side. Even the head hole (collar area) was much larger/roomier than I would have preferred it. The arm protection was an inch too long and ran right into my glove/blocker. The 7600 has adjustable arm length and collar area allowing the 7600 chesty to fit my actual dimensions (custom fit), a feature the 7450 does not have. I'm ecstatic that the 7600 is very customizable making the chesty truly contour to my body sizing.
The only CON:
All of the 7600 adjustable straps are Velcro, including over the shoulder harness's (straps), the 7450 used adjustable standard belt straps that are more durable.
The 4/5 stars for Design was because of the all Velcro strapping system, durability in this area is questionable. I rated 5/5 stars in Durability because the 7450 materials held up exceptionally well, the issue with the 7450 was protection against the quality of shots I was facing.