The major dealbreaker about Hartke is that EQ is always on, even when bypassed. And that is something that is not clearly stated about the pedal and people often overlook it.
As far as how it sounds, I haven't tried it but I get this negative impression based on the sound clips from YT that no matter what settings you dial in, you are just adding presence, those really high highs. It thins out the sound instead of making it beefier, which is what I would prefer.
Overdrive is too fizzy for my taste too, reminds me a lot of ODB-3 and is nowhere near the Sansamp's character, to which it's often compared.
If one of you guys has it and has some clips that prove my last two sentences false, I would really love to hear it.
On the other hand, I have GEB-7. It does what it's supposed to do and it does it well. If EQ is what you need, you can't really go wrong with it.