Better for pressure washing, and will give you more NET psi at the wand, not a big deal for most TMs as you can turn the pressure up to compensate, but it would be worth having (in a lighter weight) if you ran a Bane or tried pulling Valentine hose runs on a porty where limited pressure and flow were a concern, 100' of 3/8 has like 1/3 of the pressure drop as 100' of 1/4".
Come to think of it, No porty should probably be used with 1/4"....lol