Never Owned a Tube Amp and Want Advice

My expectation is that a tube amp will improve the imaging, layered sound stage, and sense of aliveness I think I hear when the treble gets better detail without sibilance.

Right. Should be fine. Only slight concern is when you say the McCormack RLD is too polite. Never heard that one myself. Had a DNA1, beautiful sounding amp. Very, very close to the Aronov and Melody tube integrateds. Very close in sound, very close in perceived power. Which there's the 150W SS to 50W tube equivalence thing. But in terms of sound, if you like the DNA and just want a little better imaging, layering and palpable presence, you should be able to find that with tubes. Any of the amps people are recommending should do that easily. 

Improved treble detail without sibilance is a sort of hallmark of tubes vs SS. The better tube amps provide extended treble that can seem downright liquid. The last guy to hear my system was into digital and while he was here kept thinking my system should be more cold and analytical. Only find himself yearning for that nice full round warm sound that was missing when he got home. So there's something about it that wins over even those who aren't naturally inclined. Seeing how this is already the direction you want to go its a safe bet you will find what you are looking for.

I’d skip the tube amp altogether and go for a class A SS integrated paired with a Tubed phono preamp. That is if your into analog/vinyl, if not then never mind....

I have owned Rogue Audio tube amp products for almost 5 years and find they deliver a sound that I prefer.
I started with a Cronus Magnum II - KT120 power tubes delivering 100 WPC. It gave me a sound that I really enjoyed over just about every other amplifier I have heard. Powerful enough to be dynamic and more than room filling with 84db and up speakers. Power Tubes last ~ 2-1/2 years or so. Bias adjustment is easy- remove a plate with two captured thumb screws and flip the 4 switches to display the current reading on the built in meter. adjust the screw with the supplied screwdriver until the meter reads the correct value.
Takes 5 minutes every 6 months or so. Usually they do not need any adjustment, just check the value on the meter.
The sound is highly refined and detailed, more neutral than syrupy, smooth with a very large 3D sound stage and excellent bass, midrange and treble.
The possible downsides are that it is somewhat large and heavy (still fits on the top of a rack or shelf), does give off some heat and can have some local hum near the amp that becomes silent a few feet away (never through the speakers). Downsides are never an issue for me and the sound quality IMHO beats every solid state amp below and significantly above its price.
The new Cronus Magnum III is supposed to be even better.  

Hi All,

I appreciate the discussion and advice.

Figuring I had to start somewhere, I decided I had to start somewhere so I found a used CJ LP66S, and will go from there.

Thought it would be a fairly low cost way to see if I can hear a tube difference and sell it down the line if I decide to change it out.

Thanks for listening,

Dsper 

@dsper 
A nice place to start.  What brand/number tubes came with it?