Master being better than the apprentice is not inherently bad. I will expand one point of Anne's answer that I find extremely important.
The master wants his apprentice to become better, so he won't do everything for him, even if he is more qualified.
This allows for a lot of situations which do not arise in the conventional "all-players-are-equal" setting.
- At the start of the task, the apprentice will ask for the master's advice. The player who is roleplaying the master will have to come up with some in-game lore-based advice.
- Even if the apprentice is good, he is bound to fail at some point. After that, the master will have to take his turn at the problem, starting from an unfavourable condition (think an apprentice knocked senseless by a Troll, or put under an effect of some evil mage's charm). This allows the apprentice to have his part of screen-time (with easier tasks), as well as some time for the master to shine and make use of his better skills (with harder tasks).
- An apprentice failing a task is also a perfect opportunity for a GM to introduce a side plot line, should you wish to introduce any.
- After the completed quest, some blamestorming has to happen: a master analyzing the actions of his apprentice, which is also not a part of usual roleplay.
- An apprentice, should the GM say so, could also get more experience from encounters, reflecting his younger age and peaking ability to learn.
