"nothing more than" and "nothing less than"
1. He demands nothing more than the best service.
2.He demands nothing less than the best service.

The two sentences are not the same.
Sentence 1 means what he demands is the best service.
I suppose sentence 2 could refer to "the best service is the least that he demands. "

How do you think about the original two sentences? Thank you!

Question

"nothing more than" and "nothing less than"
1. He demands nothing more than the best service.
2.He demands nothing less than the best service.

The two sentences are not the same.
Sentence 1 means what he demands is the best service.
I suppose sentence 2 could refer to "the best service is the least that he demands. "

How do you think about the original two sentences? Thank you!

Answer

Sentence 1 means that he demands the best service, but nothing more.

Sentence 2 means he demands the best service and nothing less, thought he may accept more.

So, in sentence two, it is implied he is more fussy, whereas in sentence one, he values service but isn't too fussy about other things. But essentially the meaning of the two is not very different in this particular case.

Usually nothing less is paired with something valuable, while nothing more is paired with something humble. This is to emphasise in the first case that the person is demanding high standards, while the second is minimising the amount the person is asking for, lessening the demand.

I hope that made sense! :)