R2 vs G2 - what features included in game is better than the other?

[V-r0cK]

2 player split screen co-op for R2. My gf and i are dyin to play this since we finished the first one 2gether. Isnt there 3 different story for R2? Single, 2player co-op, and 8player co-op? Just curious or i mitve read it wrong sumwhere.