I've been using calibre 9.1 and it works great. I have some shadows on the bot but it doesn't really bother me since it seems like it is part of the technology. I returned 4 ipads because of single dead/stuck/bright pixels.
I really like the matt finish compared to my old Sony T1 and the page turns are blazing fast.
I have the same rebooting error as other people with the SD cards but it seems like KOBO will be releasing an update soon.
I almost drove down to the states for a KPW but being able to use my epubs, having native supports for CBR and CBZ, and being expandable are all godsends.