Not pixelated at all, not sure about the negative reviews and what their issues were but I'm getting really nice quality on the IPP. They offer a trial too, so you can to try it and see what you think and what kind of quality you get.
I'm using the 7-day trial of Texture now. Granted, it hasn't been optimized for iPad Pro yet. However, I don't see any pixelation and the app looks good.