One thing I noticed is with the Sony BDP S790 is that if a source like Youtube is poor, then it cannot do much to resolve that. I mean, if someone uploads from a phone or VHS, it can only do so much with a severly poor quality image.
As for streaming HD, it excels at that. It resolves everything so finely. Very fast with Lovefilm too. A movie loads way quicker than my other Sony player BDP S570.
With a well mastered DVD, it will make it look almost like a Blu Ray from a distance of 6 feet. Yes, I know a Blu Ray has 5 times the resolution, but with some DVD'S, it creates the perception if that makes sense?
Blu Ray image is amazingly spectacular. It squeezes out every last detail.