The limited term is something that you see very commonly in various different appointments. Sometimes the terms are renewable infinitely, sometimes the terms are renewable once, and sometimes they're non-renewable.
To be totally frank, I think the consideration in assessing whether the term is renewable or non-renewable is slightly different from deciding whether the terms should be during pleasure or during good behaviour. Typically the purpose of putting a limitation on the time during which an office-holder serves facilitates the rejuvenation of the institution, the injection of fresh blood; you want people to turn over every five or ten years, or whatever the case may be, whereas the issue as to whether the appointment should be at pleasure or good behaviour really relates more to the independence of the institution from the government of the day.
I wouldn't think it would be wise to categorically say that every public office-holder should be appointed for five years and that's it, because there may be reasons—