I would also like to hear your comparisons on the Hydra 8 vs. the BP-3.5 Signature. I can let you know for a fact, the 3.5 Signature will go through some crazy "swings" in sonics the first 4 or 5 days, seem to be 80% there after 10-12 days, and about 18-20 days after being plugged in and used will be fully broken in. I currently own a 3.5 Signature, and my only caveat was hearing from Chris @ BPT it should sound great out of the box, in which it didn't :) to my ears, however make sure to give it a full 3 weeks. From my experience in power line conditioners, one word: revelatory.
Shunyata Hydra
I'm looking to purchase a used Hydra power conditioner. As I understand there have been 3 versions produced so far, the latest being the new Hydra 8. Would appreciate if someone could enlighten me on the difference between first and second series of Hydra's and how I would be able to physically differentiate them (where possible). Thanks