Perhaps just to add my experience with what Nic has already mentioned. I'm no pro on this issue, but hope this helps.
The huey does give me pretty decent results on my fujitsu S7020U laptop. At least i get more or less proper blacks and neutral looking whites.
Regarding the yellowish tone, my cross comparison between the huey and the spyder that i also use is that it produces a smaller gamut as compared to the spyder, especially in the red and blue zones. This could be the reason why there's a so called yellowish cast, but its not strong on my laptop. As Nic has mentioned, this could be due to the fact that there are insufficient levels to determine a grey balance.
All in all, i also feel that this is a usable product, but for serious work, i'm definately sticking to the spyder, which i still use on my PC. But its compactability is pretty useful as i can calibrate on the go with my laptop, though i haven tried the ambient calibrator for obvious purposes (we kindda need consistancy with photo editing ya).
*do correct me if any of the terms are wrong.