Reliability of Dan D'Agostino equipment

Can't speak to the newer gear by Dan,  but I did have a Krell KSA 50 MK I that  was very reliable. Also great sounding.  As for why Dan started D'agostino Audio, I remember reading an article about Dan and his then wife, Rhondi partnering with some other people from Madrigal.  They became annoyed  that their chief engineer was fired by some of the new partners and voiced their disapproval.  As a result, when Dan and Rhondi came to work the next day, they found the locks to their office changed.   

So began the legal battle between the D'agostinos and the Madrigal people.

Ultimately,  Dan decided to start D'agostino Audio.  His gear is really audio jewellery for the well heeled and from what I have read quite good sounding.

I have no firsthand experience with the brand, so I can't speak from experience. However, there is a YouTuber I follow whose channel is devoted to ultra high-end audio (Wilson, Magico, Gryphon, Boulder, Pass, etc.), and the members-only section of his website includes a video in which he discusses brands that have a reputation for reliability issues. I would recommend checking it out. The channel is Jay's Audio Lab. By the way, you would think that any insanely expensive audio gear would last a decade or more without issue. That's what I thought too. Two equipment failures and Jay's video changed my mind. 

If it’s electric, it will have issues, if it’s a Ferrari, power amp, 

things fail. Inevitable 

somemhould get longer life than others. 
enjoy!

I have a Progression integrated amp and is has performed flawlessly for the two years I have owned it. Before buying, I borrowed it from the dealer to compare it with my Pass Labs INT-150, and the difference was obvious to everyone that listened to it. You can't "unhear" just how much an improvement there was in SQ, so I bought it. Glad I did.

No issues with my D'Ag gear, or prior versions.  But agree with the car analogy; Ferraris and Astons still need attention, things can happen (I've had very infrequent issues with some other pricey audio stuff and I don't automatically disown the manufacturer), and owner error can be hard to anticipate/prevent.  I visited D'Ag outside Scottsdale last year, and they were terrific, gracious hosts for a nobody like me.