I was having a discussion at work today about code around weather it is more important for people(especially juniors) to understand or to have high performance code.
I am all for having less efficient as long as it is easy for anyone to understand, as it code is always handed off to junior developers to support.
I would say you should try to keep it as understandable as possible. When you hit performance issues that must be dealt with and the resolution that helps you achieve your performance goals is not as understandable, you must document it very well before handing it off to the junior devs.