I don't see much difference between A and B. One could assume that part of the "trouble" was some inconvenience to the customer.
1-This solution will save a lot of trouble and will be that much more pleasant for you.
What does 'that much more pleasant for you' mean here?
a- More pleasant for you to the extent that it will save a lot of trouble
b- So much more pleasant for you.
I think that a solution would be pleasant, but as this one also saves a lot of trouble, it is even more pleasant.