The screen's OK, once you get used to it, it'll stop feeling like a big deal, the extra pound and a half is something you'll feel every day.
People kept saying that the iPad's Retina display wasn't worth it and that they couldn't see the difference. Then quickly proclaimed after a week or more of usage that they cannot fathom going back to the iPad 1 or 2 display.
I suspect the same is true of the new MBP display. While it may seem "ok" now. Give yourself time with it and you'll have a hard time going back to anything else.
I was mostly talking about the detractors, but those that do like the display aren't exactly different in the end.
If I were a betting man, I'd say you would probably compare the old iPad to your crappy monitor. Perhaps not as crappy in terms of colors, but in terms of reading text.
It was reading text and technical PDF files that really made me purchase the new iPad. It's such a drastic upgrade in this department that I can't imagine ever going back to the iPad 1 that I gave to my mother.
My last year of college was spent carrying a 2010 Air around with me instead of the PowerBook and it was a signficiant difference in weight.
You just have to realize that a laptop isn't the only thing people carry around. So 4.6lbs isn't a big deal, but when you add it all up then the number starts to increase. Extra savings is beneficial.
Or try taking pictures/movie on the device for extended periods.
1.5 lbs is a lot for one arm to keep held in place all the time. The tablet form factor makes it inviting, but the weight makes you feel it.