I have a macbook pro which works pretty well in a pinch at home when I'm not in the studio, but as Powerdroid says, you end up cranking the brightness all the way up and moving your head around till you get what you like. I would probably say that it can work fine, as long as you create a " loop" of quality. What I mean by that is- open some files that you know are good on the laptop and calibrate the laptop until those files look as good on the laptop as they do on the regular monitor. This gives you a reference file so that " in theory" all other files will look as good. Also, you should always be looking at the histogram on a file to judge the exposure anyway, and taking samples of neutral areas to judge color. Look critically at your files when they go up on the websites, and you can pick out right away if you're off.