Without syncing all the time, my Kobo ereaders last more than a month but it will depend on how long you read (more accurately how many page turns you do) everyday.
As for the bugs and glitches, it so depends on what matters for a person that maybe it would be better for you to go and read the Kobo forum. That way you can decide for yourself if those are deal breakers.
What I like in a Kobo ereader is the ability to tweak the text look without jailbreaking the device.
I also buy a lot from Kobo, but not exclusively, which means that the ebooks are on my ereader in the blink of an eye. Yet I download and clean them for future use
I enjoyed the 650 very much before that and I think Sony makes good steady devices. I've never used a Kindle.