RT-AC1200G+ stability

I use both RT-AC1200 and RT-AC1200g+ on access point mode, and a separate router. The g+ used to be the one mostly used, but has been acting up for several months (wifi drops, refusing to connect). Never having to time to property troubleshoot it got away with the ocasional restart, until I decided to exchange one by the other.
Must to my surprise the RT-AC1200 seems rock solid, and shows very little cpu consumption and variation (although I do miss the gigabit part).
I have flashed the g+...

RT-AC1200G+ stability