Help me understand the current amp market

That's a pretty broad and tough question. Here's just one man's opinion:

Because every human ear is different- the bones in them that vibrate, the size of the chamber, the thickness of skin and bones around the ear- etc. etc. your listening experience will be different than the next guys even in the same room with the same gear. 

That being said - for me anyway, I like established brands that have decades of R&D, proven history of high quality, and committed engineers and staff as my starting point. ARC, Bryston, Luxman, Manley, Pass and the like have a hard won lineage vs. "the latest thing".  Fine audio is not like women's fashion. It must endure for a very long time and perform flawlessly and in a pleasing way. 

Brick and mortar stores are almost gone. So you should join an audio club- listen to enthusiasts rigs and decide what makes you happy. As questions, and have fun with the search. 

The better retailers will ship you a unit on approval. If you don't like it send it back.  

Gryphon Diablo 333? I would love to try the Gryphon Diablo 333, but it's a bit out on my price range,
 

@josephp732 You might consider a used Diablo 300. Still a great amp.

I’d say there is fair amount of "free riders" - make fancy box, put few Asian parts inside and I give you 100% - someone will hear improvement to their sample music. C’mon, there are amps with huge distortions built on 50 years old tech but people like them.

I have seen pictures of inside of a phono stage by a VERY well known and praised manufacturer. Literally 3x3 inch board in 40" wide case. Costs several kilobucks. For an empty box. Compare to Pass Labs XP - full of parts.

So yes, look who is in charge. Pass, BAT, Denafrips are run by engineers. They literally make gear THEY listen to. Watch out for former big names now owned by a cost-cutting corporate drones putting $5 switching power supplies into $$$$ gear.

Frankly, chasing the newest tech pales in comparison to chasing sonics that you subsequently enjoy.  Unlike high tech computers where parts can be interchangeable between manufacturers, high-tech audio deals with proprietary circuit designs and quality parts.  Even proprietary transformers make a significant sonic difference.

That being said, perhaps check out Mola Mola offerings like the Makua preamp, Kaluga mono amps, or the Kula integrated.  After reading this very positive review here, I was surprised at the very deep long resume of experience and expertise of the designer. Cutting edge for sure with great sonics to match.

@8th-note Power amps that double their power with halving their impedance do NOT have to be hot and heavy. My Class A Westminster Labs REIs are small, 35 lbs., top case runs at room temperature except for the small indented metal screen, goes from 100 watts at 8 ohms to 800 watts at 1 ohm and costs $33,900 a pair. They replaced 125 watt Class A/B voltage regulated tube monoblocks and EAR Class A 70 watt tube amps (after 50 years with only tube amps). ASR recommendations are for inexpensive gear. Amir does not promote the best/better gear which is relatively expensive but not uber expensive like Westminster Labs. 

@zlone I am keeping a tube pre-amp for the added warmth to the REIs which are just plain neutral and pass-through upstream source and component sound. Funny thing, the manufacturer/distributor of the Saunders Magatech who sold the company and is the sole non-Asian distributor for Westminister Labs products is the same Garry Leeds of Hear This.