McCormack DNA-750 good?

Thoughts? where to find a review? Considered a top tier amplifier?
Any info is appreciated, there is not much in google land as far as reviews, or much of anything.

I own a pair of these amps. All I can really say about them is that they sound very good from top to bottom.

They do have a lot bite.
They do not run hot like Class A amps.
They have lots of power and will drive any kind of speaker.
The reason I purchased them is because my speakers are Aerial 7bs and require a good amount of current.

They are large and heavy 65 lbs. each.

If your speakers are difficult to drive these will do the job. There are lots of different amps out there to choose from it is a matter of preference. Mitch2 is correct they were designed by Conrad Johnson.

Upgrades are done by Steve McCormack starting at $1000 to $10000 per amp.

I spoke with Steve about how much difference in sound quality from stock to upgrade. Unless your willing to spend at least 2000 and up there is no significant difference.

Your question are they on par with reference amps, depends what you classify as reference amps. Like I said they are very good amps.
Are these on par with pass labs, Macintosh , etc etc. ? Or, are these not in the same league?

From what I have researched/heard, these are right on par with the big pass & Mcintosh, I just wanted to get other opinions, and as many as possible.
I don't know whether they are on par with Mac or Pass labs I have not heard those amps, but I do know that pass labs is in a league of its own. If money is no object then go for the best.
Money IS the object. I would buy used. Which is why I'm looking at the McCormack monos. Still considering them. Are they worth a purchase in everyone's eyes? Or wait? Buy something there better?

I'll probably purchase t hem, they are in flawless condition. Only concern, is they are from 2009, and getting old, no warranty left.
Since you asked, I suggest you not rely on "everyone's eyes" when making your amplifier choice but rather rely on your ears. I suggest you listen closely to the 750s before you purchase a pair. I have no doubt they are powerful but they also do not have the universal reputation for musicality of the older McCormack amplifiers (e.g., DNA-0.5, 1, 2, 125 and 225 and 500). I would listen to any of those you can in order to gain perspective and to form an opinion.