First off at no point during my reading have I been bored. Each volume is told in a different way and play out much more different than the previous volumes. The first four volumes were written in a way that expressed urgency. This provided non-stop action and suspense for the flow of the plot. Volumes five through six however seem to be more laid back and without the characters we have grown to love can be a little painful to read through.
To clarify something real quick, volumes five and six are part of one story that takes place in Gun Gale Online (GGO). The transition from volume five to six is seamless and instant. So what to talk about; unlike in SAO and ALO, the weapons used in GGO are guns that are biased off of their real life counterparts and some fictional ones as well. The story is once again biased around Kirito who is asked by one of the officers that helped out in the first story (SAO) to go into GGO to find a character who supposedly can kill someone both in-game and in real life. Within the game he meets Sinon who teaches and helps Kirito become accustomed to the game fairly quickly. Now there were a lot of things that I liked about volumes five and six but lets start with the negatives.
First off the pacing seems much, MUCH slower than the previous installments of Sword Art Online. For one thing even though the timeline for this story arc is only a week or so, the story takes way too much time explaining Sinon's back story and also ramping up to the climax. Another negative thing is that other than Kirito, there is no returning characters that play a huge role in the story. You have Kirito and Sinon...that's it. We invest ourselves into saving Asuna and once we achieve this goal...she sits on the sidelines...? It's strange why the author would do this because in this volume(s) he pulls an Ash Ketchum and totally makes Kirito powerless in this new world (well at least in the beginning chapters). His overall personality in this story has changed from a person whiling to risk his life to a very passive and shy person. His overall intensity from SAO and ALO is completely gone. The last overall negative for me was how much that I didn't care for Sinon. They dedicate a whole long chapter to explaining her situation and life and I ended up caring this much (--) for her. I didn't like her personality or her way of doing things.
So positives; I really like the world of GGO (not as much as SAO but a hell of a lot more than ALO). A whole MMO world biased around guns? Freaking awesome if you ask me. The barren desert setting that the author described really made me wish that such an MMO existed in today's world. The tournament they hold in the game is another thing I really liked about this story. Something lacking in the previous volumes was the inclusion of a lot of PVP (player vs player) battles. There were a couple in SAO and almost none in ALO so it was nice to have such a PVP focused game as the setting for this story. Other than that however ends the positives.
Overall I still like the story surrounding the mysterious gunman that could kill someone in real life through the game. The story's pacing was much slower than I would usually like and it had characters that I didn't particularly like but hey it was still enjoyable.