The other interesting differences to note are that Echoprint doesn't use a constellation fingerprinting approach along with offsets, and the fingerprinting is meant to be the same across all platforms / use cases so you can compare them.
As a direct result, you also can't get the offset in seconds that your query audio refers to like you can with Dejavu.
When I coded up this project, I wanted something that was more customizable - allowing you to decide the speed, number of fingerprints, size of the fingerprints etc to match your own false positive / memory / CPU requirements.
When you do, you sacrifice interoperability between all Dejavu index installations, but you gain that application specific performance. It of course depends on your use-case which library is better.