Better sounding after 1 hour

I noticed that after 1 hour my Cayin A-50T tube integrated amplifier sounds more open and dynamic. Is this a particular characteristic of tube amps?
Years ago when I got my Rogue Cronus Magnum, I couldn't wait more than 15 minutes for it to warm up the first time i used it. We started spinning tunes and it was mediocre at best. About 10 minutes later it opened up to the point I was practically in tears. I can't imagine what it's like for these people with much higher end gear. Yes, tubes do that.
Tube gear usually takes about an hour or so to warm up and sound it's best. Soild State can take 4-12 hours to warm up to sounding it's best, which is why many who own SS gear leave it powered up 24/7.
In your own experience at what point (# of hours playing) do you get maximum sound quality from your tube gear? Does the sound also deteriorate after several hours?
I have come to agree with Elizabeth, I leave my ss amp and tube pre/phono on 24/7 for best sound. Most of my tubes have lasted for years with no problems and the pay-off is a consistently good sound.
It's common in all higher end gear, and some can take quite a bit longer. Had a McIntosh C2300 tube preamp that took over 3 hours to really sound right. Some folks will leave their stuff on 24/7. Transistors are usually a bit faster to warm up, but not always. I've heard stories about early Krell amps that needed 4 or 5 hours of warm-up.