The 10/11 and 11/12 are the exact same besides colors. The 12/13 changed to a slightly different toe strap system. I haven't tried the new ones so I can't comment on them, but I've owned 10/11 and 11/12 versions and they have worked great for me. I went through the same thought pattern and decided it was not worth the extra $85-$110.
14 NeverSummer Proto HD . 13 Never Summer Cobra . 12 Gnu Rider's Choice C2PTX
13 Now IPO . 12 K2 Formula . 11 K2 Formula
13 NB x 686 580