To JRL's very complete answers, I can only add that the screen is a two-bit (four level) greyscale passive LCD. The screen itself has no unusual failure modes. Even the ribbon cable seems to be less unreliable than in the earlier 1xx series of 'books.

Since the 150 came late in the series, many bugs had been worked out, and the components are also capable of overclocking to a greater than normal degree. The nominal clock speed of 33MHz doesn't come close to stressing the CPU, so reliable operation at 40MHz is commonly achievable.

Despite its "Road Apple" status, the 150 is a serviceable machine, especially because of its ability to use commonly available IDE drives. Just make sure the 'book comes with enough RAM to run whatever it is that you intend to run. It's hard/expensive to find compatible RAM out in the wild.