question to Plinius Amp owner

Just curious to know what is the sounding difference you experience when you switch between class A and class AB? I guess this comparison might be more objective since the rest of circuit is the same except the bias. Can you confortably draw the conclusion that class a mode is better in every aspect ?
I leave my Plinius on AB 24/7. When I want class A it only seems to take a short 5 minutes to start soundind better. 20 minutes it's good to go!
The owners manual says to leave it on. That is what I do. When you want to listen critically switch to class A. I usually start listening right away and the sound just keeps improving.
Thanks for the responses !
Let me try summarizing and adding as follows:
1. A well designed class AB is still not as good as a well designed class A, looks like the difference is not trivial
2. the above might be applied to dynamic biased class A
3. based on my experience, it takes 45 minutes to 1 hours (depending on the environment temperature) for Class A amp to reach the thermal equilibrium where it is designed to operate at.
4. "always on" might not be appropriate unless you do not pay the electricity bill
UPDATE: I leave my amp on class AB, 24/7. When I flip it into class A, it takes a good 30 minutes to really stand out and become very dynamic.