The AH-64 and the AH-1W were originally designed and used for very different missions. AH-64's were designed for deep attack while the AH-1W operated close in, in direct support of troops. The Army's concept of deep attack initially worked well in the first Gulf War but proved disastorous the second time around in Iraq. AH-64's now perform escort and close support duties just like the AH-1W but with all sorts of complex sensors they needed for the deep attack mission that they no longer perform. Hands down the AH-1W has to be the better aircraft for this mission. Less complex, lighter, easier to maintain, and does better in combat conditions.
It always seemed the -64 was designed primarily to keep the 15 Romeos very busy....