If anyone wants a nicely priced way of reading digital comics I'd recommend a Nvidia Shield tablet coupled with a nice 64gig class 10 microsd card.
The shield costs 150 and the card 18 quid from amazon. I also bought a smart case for about 7.50. Here's the skinny.
Lovely screen. It's 8 inch, really sharp with excellent vibrant colours
Bastard fast. Page turns are silky smooth and comics load up nice.
It's also a gaming tablet that in benchmarks comes out almost as fast as an iPad Air 2 for a fraction of the cost
It's only got 16 gig of internal storage which means currently limited space for Comixology stuff. However Comixology have SDcard storage on their roadmap to be done at some point. Also Android Marshmallow has a feature called Adoptive storage where you can convert your microsd card into something the tablet considers internal storage. However currently there's a mega serious battery drain bug in Marshmallow on the Shield that Nvidia haven't fixed yet.
I've got Comixology, Kindle and for cbr/cbz I'm using Comicrack which is a rather nice and featured reader for Android. Bit of an odd UI to get used to though. I'm using the free File X-Plore to connect to my NAS and pull comics across to the SD card over wifi.
I got my Shield from DABS but Amazon are getting them back in stock later this week. One thing to note. Nvidia have pulled a Nintendo and the box just contains the tablet. There's no way of charging it all all so you'll need a microusb cable that can charge and a charger. OS wise the tablet is almost stock with just a few extras from Nvidia preinstalled.