I was really worried about the art quality and small screen when I bought my laptop last year, but so far, it's worked out fine! I think the main thing that's helped is having a really flexible tablet- all of the landscapes I did last year were done with a mouse, which hurt the quality/design flexibility a bit.
I think it'd kill mine too, actually >_> I've only attempted it once or twice, but I hear the pros work in ridiculously high quality, and that I should start trying to take a stab at it. EVENTUALLY! And yup, 300 is standard print quality, which is why I started to work in that. It's worked wonders, I used to work in 72 and could never get the results I wanted.