Hi Yuriy,
to me the first form is a list of simple rules.
The second one is a complex expression
You made an effort to keep the list format for the second expression, while violating traditional block formatting which would be
��������
^ backgroundColor isNil
or: [
�� �� �� �� �� �� �� �� (backgroundColor isColor and: [ backgroundColor isTranslucentButNotTransparent ]) or: [
�� �� �� �� �� �� �� �� borderColor isColor and: [ borderColor isTranslucentButNotTransparent ] ] ]
I don't think that runtime optimization count at all in such choice.