Debate: Class D amps need 48 hours of warmup

OK, guys, I know this is sounds like a weird question, but lets’ not attack the replies, or even the author, until we’ve seen informed replies.  This kind of judgementalism is really not what I was looking for when I posted. 

Not an attack at all, maybe to the manufacturers if they create an amp with a 48 hour warm up time to sound good. 

I have heard from dealers that they can hear a difference in the sound of amplifiers that had been powered off when the store was closed for a few days and that they return to optimal after 48hrs.  

This begs the question- how does optimal compare to our usual "startup" period when it starts to sound  good?  My amp and system sounds great after 20 to 45 minutes or so- whether tube, class AB or Class D.  I am completely satisfied with the sound after that. 

Since I have never left electronics on longer than 12 hours or so- I do not and probably will not ever experience a 48 hour warmup.  Is the original question 48 hours to sound good? 

I have owned a variety of pretty good amps in Class A, Class AB, and Class D, but not tubed amps except for Lamm's hybrid M1.2 Reference (one tube each).  Of the amps I enjoyed having in my system, they all sounded pretty good within a few minutes of powering up and good enough that warmup was never a consideration after they had been playing music for about 30 minutes.  If I couldn't ignore the gear and enjoy the music after 30 minutes, I would question whether I actually liked the sound of the amps in the first place.

When I had Class D amps, and with my current my Class AB amps, I rarely turn them off except for thunderstorms, vacations, and long weekends away from home.  I did turn off my Clayton M300 Class A monos most days, and those are the amps I owned that probably benefitted most from warmup but still, 30 minutes or less and I wasn't thinking about warmup.

They run cool anyway so the point is moot.

Interesting. I literally just powered up my Class D’s mono blocks after turning them off on Thursday. (Was gone all weekend) And usually never turn them off.

I notice no difference  

My Marantz PM10 stays on 24/7.  Although I can't say it sounded any different when it was first turned on after being off and unplugged for the best part of 6 months when we first arrived at our second home.  It just sounds good even in comparison to my much more expensive Class A tube main system.