I strongly recommend going to an Apple Store to compare the two side-by-side. I initially got the hi-res 15-inch but quickly found that the text size was just too small for me. I tried increasing the font size, which you can do in most apps, but the issue for me was the browser. While it makes text larger, zooming in web pages makes images look pixelated, which I didn't like. And on top of that I didn't like the idea of having to zoom in every web site I visited (though you can get browser plugins that automatically zoom every site, which is what I did). The extra space and increased sharpness and clarity was definitely nice, but the small text size and having to zoom web sites convinced me to return the hi-res model for a standard res model. I'm really happy with the standard res so far, but I've seen plenty of people have no problem with the hi-res. It depends on the person, so I would highly suggest seeing the two for yourself.
Good luck!