Recently I started on my first job as a junior developer, I had a more senior developer in charge of mentoring me in this small company. However there are several times when he would give me advice on things that I just couldn't agree on (it goes against what I learn in several good books, questions I asked on some Q&A sites also agrees with me) and given our busy schedule, we probably have no time for long debates.

So far I have been trying to avoid the issue by listening to him, raise a counter point, and he raise his original point again (most of the time he will say best practice, more maintainable but just didn't go further) I take a note (since he didn't raise a new point to counter my counter-point), think about it at home, but didn't make any changes (I'm still not convinced). But recently he approach me yet again saw my code and stuffs and asked me why haven't I change to his suggestion. This is the 3rd time in 2--3 weeks.

As a junior developer, I know that I should respect him, but at the same time I just can't agree with some of his advice (I don't like his programming style too but that another issue). Yet being pressured to make changes that I think will make the project worse. Of course as an inexperienced developer, I could be wrong and his way might be better so my question is what ways can I do to better judge if a senior developer advice is a good or bad/outdated one. And if it is a bad one, what tactics can I do to not implement it his way despite his 'pressures' and to convince my boss who is more likely to trust him?