As for page down, I think the nicest piece of it is that when I hit page down, I know exactly where to reset my eyes when reading something that's longer. Now, space usually worked in safari, but it was suprisingly unpredictable. Of course, pages meant using option+up/down or scrolling.. We all have our quirks, I guess. :)
I have the upgraded 1600x900 screen, so I can't speak to the quality of the lower resolution screen. I've heard it isn't as good, but I will say that for programming, the 1600x900 has been great. (I forgot to mention how much I hate glossy screens as opposed to matte...) From everything I've heard, the upgraded screen is much better.
Thanks for the heads up. I'm not sure yet whether 1600x900 is the right choice for him; Windows software is still not as resolution independent as it should be and he needs rather large text. I think that the retina pro would actually be quite good in that aspect because the scaled resolutions are very well implemented there, however $2.3k for my father's usecase is quite a stretch ;).
I have the upgraded 1600x900 screen, so I can't speak to the quality of the lower resolution screen. I've heard it isn't as good, but I will say that for programming, the 1600x900 has been great. (I forgot to mention how much I hate glossy screens as opposed to matte...) From everything I've heard, the upgraded screen is much better.