To me it'd be a tough call as you already know. Both are longer travel trail bikes, both can be ridden on XC, specialized has the 4-bar linkage, Giant has the swinger shock, both have disc brakes etc. If it came down to it i'd get the Enduro for the fact that it doesn't have the first year production shock on it, and i am very biased towards true 4-bar bikes(i love my FSR)