i doubt it's reliability in the long run. i'm using Beta Aivin's adapter. powers up to 800mA. might look minute (like the size of a Nokia adapter) but it's very cheap and reliable.
like what subversion said, it's really very noisy. so much so that once, the boss of a jamming studio requested that i stop using the multi-purpose adaptor for my pedal. he said it was causing too much noise.