Timid is good for special attackers who benefit from speed. Sylveon and Espeon could both benefit it, though they would both have the ability to benefit elsewhere. For instance, some extra speed isn't going to help Espeon face Greninja, but extra defense probably will. Though against pokemon of a similar speed, extra speed could benefit a lot.
Its entirely personal how you go with your team.
Its entirely personal how you go with your team.