Picture quality is really good. I had it side by side with my iPad 3 which has a retina display and its slightly sharper.
I would say that you should play around with one before spending the cash or binding yourself to a contract. Depending on peoples needs, they have different opinions about the tablet. If you're really stylus dependent and love to draw, sketch, take notes etc, this is a really good device.
I know a lot of people who bought this and have hardly used the s-pen. The slight lag people speak about isn't bad at all. When i got my tablet i was expecting it to be a lot worse. I switched off all the unnecessary sensors and stuff that slowed it down. Works perfectly for me. Besides this, i heard of an upcoming update which addresses performance.
Like i said, best thing is to play around and get your own opinion of the device. Just take into consideration whether you plan to use the stylus more often or not as well.