If my opinion is different to my parents, then I will take theirs into account but in the end I will act upon what I think is right for me and hope that eventually they can see things from my perspective too. I think that this is still filial piety because I am still listening to my parents advice before I make a decision. I will still respect their views even if I do not act upon them. I think it is important to listen to them (even if you disagree) and to also explain why you disagree in a calm and respectful manner. Disagreeing is not disrespectful by nature. It is HOW you disagree that can be the problem. If you scream and shout or do something out of spite, then this is not filial piety... but if you consider your elders viewpoint carefully but then still decide to act differently to their advice, I think this is acceptable.