I enjoyed this season too.
It obviously suffered from two huge issues though:
1. Reaching the bar set by previous seasons. If you're going to compare it to the previous four, then yes it wasn't as good but it's still very good by todays standards.
2. It's being adapted from the B*@ks, which haven't even been finished yet. It's going to be incredibly difficult to keep the storyline charging along at a good pace while still building characters and no doubt missing out huge plot devices while trying to steer the whole storyline on course and keep all the storylines along a linear path.
One thing I think this show could have really benefitted from is having a second show running alongside it (an animation) which can add depth to characters and storylines without adding huge costs to the budget like additional episodes would. They could have told more about the history of the houses, Brienne's life, Stannis' previous battles, Ned and Roberts earlier days, Littlefinger and Varys' early days, The Hound and The Mountain's former years, Cersi and Jamie, the Targaryens ect ect.
It's what they did to build the Matrix world back in the day. There was a huge amount of information about the history of the characters and the Matrix which really added to the sequels for anyone that actually watched them before hand.