DMC4 wasn't that easy. It was frustrating because of how much damage enemies would soak up, so that made it harder than it should be. I am someone who considers Ninja Gaiden 1, DMC1, and God Hand as the three top tier 3D action games. DMC3 comes close to DMC1, but I still like DMC1 more. NG2 is nowhere near NG1 for me. As much as I think core gameplay is important, just having good core gameplay with shitty levels and enemies ruin it. NG2 had this problem, as did DMC3. Sadly there won't be a God Hand 2, so I don't think that will ever be topped. A true Ninja Gaiden 3 also seems unlikely. Bayonetta could turn out great, so hopefully it does.
Oh, and NG2 is better than DMC4. DMC4 sucked for the most part.