besides not making you look like a newbie, its not as hot, it offers refenorced elbow padding, and on the DYE CORE jerseys. they have extra chest padding.
and its not a firm/stiff materal. Jerseys are made to promote bounces and "skiming" the paint off of you if it comes at a high angle.
I play woodsball in my jersey, never had any problems, but it could happen. The DYE Core line have been marked as "made for cheaters" because of all the extra padding and things. It seems as if it's been made to induce bounces.
around here, dye and proto jerseys are banned (in tournies) if they have padding, because of bounces. all padded jerseys are banned for tourny use here, but for rec, no one cares.