I absolutely fed up with Kobo firmware.
After I made the mistake to upgrade from the factory firmaware that was shipped with the Kobo Glo I had had constant bugs and problems.
Although I believe the overall UI is now better,it came with a cost.At least for me.
In the last 6 months I had two serious situations that required to factory reset my device.One of them was quite persistant.
Also until now there wasn't any patch that was relative bug free.The last one(8.1) introduced a bug that doesn't activate the light when is in 1%.
I must increase the luminocity to 4-5% first and then press again the button.
All in all,I was much happier and carefree user with my Sony.I wish Sony introduced a proper reader.
Maybe a Kindle(or a Pocketbook) is a better option for my Xmas shopping spree.
btw:I have relative little experience with kobo,my first(and I believe last)device is the glo.I don't know what was the firmware in the older devices or in the mini/aura HD.