This video compares the Maxon OD808 vs the Maxon Overdrive Pro and the Maxon TOD9. These pedals do sound very similar in some ways and are very different in others.
The Maxon Overdrive pro is one of my longtime favorites. I have used it on and off at live gigs for years. The TOD9 is a new pedal to the collection and features an extra "tube" drive control which allows for higher gain tones. The Maxon Overdrive Pro is a monster for clean boosting your signal or as a rhythm dirt tone.