I'm going to try and stop by the Apple store today or tomorrow and just pick up the Pro to get an idea how much an extra pound-and-a-half feels like.
On the retina display, I had a MacBook pro 15" with the optional 1680×1050 matte display for a while (I was relieved of it, along with my iPad, iPhone, and iPod on a car smash-and-grab, a very iBad day.)
While the display was gorgeous with some apps, it was annoying on others, and especially annoying while surfing the web. Lots of semi-poorly designed websites with small fonts became unreadable by default, and I was constantly command+plussing to get readable fonts, or using browser features and extensions to increase the minimum font. But zooming bumping the fonts often caused other problems with site formatting, and it was overall a bit of a pita. Take this web page for example... If the text input box had a way to small font, bumping the font size also bumps those silly little emoticons below the text box, and would push the page into horizontal scroll by the time you got the font to an easily readable size.
And I also suspect other applications that have small default fonts or unchangeable font sizes are going to be very difficult to use until they are updated for Retina.
Again, something I hope to check out at the Apple store...