Really not much can be said about this that I don't think is new info. The core kit is great and honestly should have been in the HG line up of Bandai kits as it's not really a 30mm build at all.
The only down sides are the arms very limited articulation and the shield connector is only on one arm so if you do buy option parts keep that in mind when your building them as the left or right handed versions.
I also picked up an accessory set (the one with the Gatling gun etc) No issues at all and no drooping etc.
All in all if you just want one simple AC6 kit this isn't a bad option and is a lot easier and cheaper to find.