It is true that the gameplay got some tweaks and refinements, it might work out just a little smoother than in GoW 3. Best gameplay mechanics in the series so far? maybe YES. Is it more fun to play? NO,
GoW 3 had so many memorable and epic moments, Ascension never had a chance to top that. It's not even close.
It's still a great game every GoW fan will love and everybody can enjoy though.
Edit: I see how everybody praises the story of GoW. Lol, the story was always as simple as go there and kill that. The enemies, its scale and the battles they provided was what made the games epic. Every GoW raised the bar in terms of scale and powerful enemies, since Kratos got stronger. It was relatively "easy" to beat the previous games in each sequel, with GoW 3 being the ultimative battle against the olymp. How could they go wrong with that? (Not saying everybody could make GoW 3, but with SM's talent it was only natural).
Now Ascension was the exactly opposite. It was a prequel so it would be the weakest Kratos so far, he would face the less memorable enemies, because he would face the real amazing ones in the "later" games. I'm sure it was the most difficult GoW for SM to make an appealing plot with the epicness everybody expects from this brand. And they did it pretty decently, just not as good as GoW 3 and even GoW 2 imo. Because it was impossible.