I use the GT7dot7 for a large amount of manga reading and some comic reading. I used the nook color before this and a 4 inch phone before that. I used to use perfect viewer as most people who try it end up using it since it is the most powerful comic reader and functions very snappy on most any device. I have since switched to komik reader for the gtab and i personally use it now as my only reader. I am a sucker for smooth page turns and komik allows for very smooth sliding of each page to the next. Where as perfect viewer allows for very quick and responsive page turns but there is no smooth scroll option.
Reader aside i have absolutely no problem reading on this device, it is a great size and it has a very crisp screen. I read though all of engadget distro with no zooming needed. Also, Google currents works great for reading stuff around the web, again the screen for me is the perfect size for it.
Device: Nexus 5
ROM: The one with Android 4.x