I have owned a Blackhawk MK3 for a few months. It's very nice, refined, and responds well to tube rolling. But, personally, I feel that it does not rise up to the level of hype created around the Raven products, at least the Avian series. It competes favorably with Primaluna but is not better or worse than other tube amps in this price category.
I know that Raven likes to claim that the 20 watts produced by the Blackhawk can be compared to 100 solid state watts. Nope. The first 30 watts in pure class A that my Luxman produces run circles around the Blackhawk, not just in the bass department but also soundstage, imaging, and ... well, pretty much all areas. Secondly, the separate subwoofer connection is rather gimmicky in my opinion. For example, using REL's preferred method of speakon/high level connection still sounds better.
Don't get me wrong, this is still a very nice component, and very good value for the money. But giant slayer or 'punch above its class' it's not. It's made in the USA, and competes favorably with similar priced amps from other countries, both in terms of quality and cost. This was honestly my motivation to buy, not the hype.
Disclaimer: I have been using it with low sensitivity speakers (Harbeth and Sonus Faber), so it might be a completely different beast with higher efficiency ones. But it certainly doesn't have the juice to drive low efficiency speakers to their full potential.