well well, where to begin. My experiences are easy to sum up;
I'm obviously DEAF! While at Lima I had the oportunity to hear some of the best systems available today. Built with horns and tubes.
For my money the Pi speakers are on top. I heard differences when speakers were changed on amps. but when amps were changed on the same speakers, I'm sorry to say that within few minutes I cant hear much difference if any. There was one time in particular though, when a 300B amp was changed out for a pair of 45's. A tremendous difference in that case. Was it the 45 tube or the way that particular amp was made? I couldnt say. Before the 300B's were put into service there was a different amp. on that change over I didnt notice anything.

So why did I get a tube amp you ask? Nastalgia my friend. They are not single ended, but there is a lot of them and they look great! after only a few nights listening I cant notice any difference. Mind you i'm using my Denon as a preamp because I dont have not a tube preamp yet. So, right now the push pull Dukane amps sound like the Denon, but I get to heat up my living room and have a litle candle light to read by!

I cant sit on my couch and listen to talk radio. Like you though, I can sit and listen to talk radio on one of my old tube radio's all night, and often do!

This is a Hobby for me so when I build my own 300B or 2A3's some day, perhaps after having it in my listening room for an extended period of time, as oposed to stopping by for a quick listen, I too will be able to hear some more of these subtle differences.

And now that I'm begining to turn this hobby into more of an adventure by starting to make wooden horns. I listen a little more carefully to all the sounds that are there, and all the sounds that I thought were there before that last change. That kind of listening is different from sitting back and enjoying though. I find a difference between critically listening to the machines, and just sitting back.

As for the Denon? a component sytem was out of my budget and to be perfectly honest. I love to listen to the movie sound tracks during the films and it was time for an HT upgrade. I get to relax with a movie and listen to great songs, nice dialogue and special effects all at the same time. The denon was my choice over a half dozen other receivers I gave a listen to. a couple I noticed some differences, and others I heard no change, but this one just won out. The pro audio stuff I have is older and good for jamming, but I have hum and noise with my older stuff and rack gear was not going to be popular with the wife in the living room!

I like it all! Home theater, Well crafted tube gear, CD's, Vynal, High efficiency speakers.
why hell, I even get a charge out of electrostatics!

Bill