Jackson is really good value for the money. But as with all guitars in that price range, there may be bad apples.
If at all possible, check the guitar out before you put down the cash. If you order online, check out the return policy in advance.
Check so the finish is even - especially around the neck pocket area. If the neck has binding, make sure it's also evenly bound all the way. There should be no gaps around the inlays and the frets should sit flat against the fretboard surface. Check the guitar for cracks, etc.
Test play it without having it plugged in and make sure there's no buzzing or dead spots anywhere on the fretboard.
And finally, if it comes with those Duncan Designed cheapo pickups, you may want to replace them sometime. Some people say the EMG-HZ that come with some of the MG-series models are on par with real Duncans, but that is surely a matter of opinion.
'bane