The benefits include an increased level of liability protection for you personally from the activities of ABC, LLC, and potential tax advantages or saving opportunities may exist. There are a lot of things to take into consideration when arranging businesses like this, so I would be beneficial to not only continue speaking with your tax specialist, but setting up a meeting with a business attorney would be very valuable. Many attorneys offer a free initial consultation, so take advantage!
I agree with Mr. Warring.
No attorney-client relationship is created as a result of this submission. The information and answer provided is of a general advisory nature based on the limited information provided and should not be constured as formal legal advise.
As a parent-subsidiary relationship you will not get the same creditor protection benefits as if you keep them completely separate. If you keep them separate and one of them has a liability, the assets of the other may escape liability for the problems of the first one. The tax benefits are irrelevant if they are both taxes as flow-through entities.