As stated in the title it IS excellent.
However I pretty much find myself more or less using just the standard diodes - so was it really necessary to buy the most expensive version of the J.Rockett Archer?
Obviously not, but knowing me if I had bought the standard version I would dwell forever on how the other diode settings in the Archer Select might sound .....
For me (using a Gretsch 6120T into a Deluxe Reverb) it has the perfect rock sounds and cleans up nicely using the guitar volume knob, think Black Crowes/Ian Hunter etc., with the standard diodes, pushing an already slightly overdriven amp is where it REALLY shines - which according to Guitar Player interviews with Bill Finnegan was the intended use for the Klon Centaur.
The alternate clipping/diode settings, apart from one being significantly louder and cleaner they're hard to describe and the miniscule differences in tone and clipping characteristics are best heard with the clipping knob somewhere above 12 o'clock.
Sturdy and IMO well built, all functions are pretty obvious, even the DI out sounds good.
So - does it sound like a "real" Centaur (yes I know everyone says Klon which is the name of Bill Finnegan's company)?
Likely, never even seen one in real life but judging by U-tube comparisons - yes.
Cheaper alternatives: obviously the standard Archer and for those who want "more" I highly recommend trying out Wampler's Tumnus Deluxe which can take a humble sounding Tele anywhere from slight OD to bonecrushing metal.