Done with 1/2 the people (if not less), on PSP hardware... and yet your review pretty much compares it dead on with it's bigger brothers on the PS2. Is it fair? Overall I'd say no, then again I'm coming from a biased view point. I think it's a testament to how close the hand held game got to the previous games.
I think other reviewers said it best, "If you're looking for GOW3, you'll be disapointed but if you're looking for GOW on the go you'll be hard pressed to find a better PSP game".