Little mouthpieces

Hello everyone, sorry for my french english

I learned French Horn with Philippe Durand for 6 years when I was a kid

I start the trumpet 7 years ago (4 years with a bach 7b, 3 years with the yamaha11b4 similar of bach 7d)

I think I finally find my sound since 2 months, 

So 2 months ago I changed my mouthpiece to find the one that make me play with the less effort

I m not sure about this :

The little rims create a pressure more important, so you can use it and relax all your muscles

The mouthpiece do a big part of the pressure work instead of you

So you really can relax all the points of your body that you used to create this pressure 

I read also some comments on internet on little rims that i really think are not true

Not true : little rims are for little lips, this is not true

I want to know if some of you are agree with that, 

How do you choose your mouthpiece

What are you thinking about little rims ? 

Why it is not more used in schools ?

Do you think little rims have inconvenience, if yes can you explain it  ?