As I mention in my review of the Psychics Handbook, I feel that it has a flatter power curve than typical D&D magic classes... that is, it starts out with more power than a magic-using class of the same level, but slowly falls behind.
This may make the balance a little uncomfortable for D&D, but it seems to fit pretty well in a D20 Modern campaign, where the onset of magical abilities is usually delayed until 4th level, and spellcasting abilities are capped at 5th.