Leave tube amps always on?

I just bought a  Black Ice Fusion 3502 P Stereo Tube Power Amp (formerly Jolida) to replace my old Rogue Model 88 Magnum that took a dump for like the third time so I didn’t want to invest another dime in that amp.
The Black Ice may not be in the same class as the Linear Tube Audio but it sounds great to me. At least better than the Rogue.
The manual for the Black Ice states that they do not recommend leaving the amp on 24 hrs. a day as is the custom of some audiophiles to achieve max sonic performance on demand. While this is often recommended for solid-state equipment, Black Ice does not recommend this procedure for vacuum tube amps.
Now, there is a power switch on the back of the unit and one on the front panel. The one on the back is to be left on all the time. To operate the unit, press the switch located on the front panel to turn the power on. The indicator will flash red. Within a few seconds (seems longer) the tubes will begin to glow a soft orange color and the power switch will turn blue.
This was taken from the manual. I’m not exactly sure what is happening when the power switch is flashing ’red’ when first turned on but I assume that it’s some type of soft-start circuitry? I may be wrong as I don’t know enough about electrical engineering so I’m making an educated guess.
Anyhow, the manual clearly states not to leave it on all the time to preserve tube life.
Take that for what it’s worth but it seems like good sound advice coming directly from the manufacturer that I’m all too happy to follow.
If I plan to listen on and off during the day, I leave the amp on until I’m done for the day. It seems like it takes only about 5-10 minutes to warm up. But, I haven’t really evaluated the sound immediately after turning it on as I assume it’s not going to sound it’s best anyway so I usually give it 10 minutes before listening.

@nicktheknife 

i am surprised to hear of the unreliability of the rogue audio unit in your hands

was it an older or well used unit?  did you try to have them fix the problem?

i have had a eye on rogue, as a good, made in usa, brand of tube gear - the brand seems to have quite a few proponents on this and other forums, was perhaps going to try one sometime

now this gives me a little pause

Such a fuss over a simple idea that’s backed by listener experience. Argue if you will about how much is costs to turn-on/off, replace tubes, etc. people who leave their gear on report better sound in the first hour or so. That’s the complete nut.
We’re mostly at home now. Why not leave your system on for a week and see what it sounds like?
Just askin’.

PS Old tube lover now running solid state. I never turn off anything in my system.

As the OP, I started this weekend - turning amp and preamp on Friday after work, leaving on, and will be turning off later today Sunday. During the week, will turn on and off normally.

Its probably in my head, but it sounds better today than the past two days. 

@ jjss49
The Rogue Model 88 is an older amp. I bought it used. Not long after that, I had a problem and notice the ceramic (?) resistors had cracks in them. Rogue ran me through some checks using a digital ohm meter and at least one was bad. They sent me a bunch of replacement resistors and I soldered them in myself. Pretty easy. I then had a problem with a channel in my Rogue Model 99 pre amp which I sent in for repairs. They only charged $125 which is their bench fee because the parts weren’t expensive. I also had to replace the bridge rectifier in the Model 88 Power Amp at least twice. I did that myself also. Then, I had a problem with the power amp sounding very distorted/scratchy in both channels and would just blow both channel fuses. Sent it in. Rogue replaced some resistors and when I got it back - same thing. I then replaced the entire complement of tubes and still no help so I decided not to spend more money on it and put towards a new tube amp. Shipping the amp wasn’t cheap either. I also have two solid-state amps but I like my tube amp the best.