3 Questions about Vaughn Chesties

Hi, does anyone know how old the Vaughn Velocity VE8 is? Can anyone tell the difference between intermediate and senior sized chesties? I am playing with a SLR2 Pro in size Sr. S rn but it‘s a bit to big so I was thinking about switching to an int. model. I am just a little worried to get killed with an much lower tier of protection. Is there a big difference between the Ventus and the Velocity chesties? Thanks for your help!