I think it's a personal preference - but also the subject matter can make a big difference, or even a different view of the same subject. For example;
Here I used a longer exposure to get milky water as I thought it showed better the different textures in the shot - milky water, rounded stones/pebbles and jagged rocks.
But here, the same rocky ledge at Kimmeridge but from a different angle, and a sense of movement in the water works better (in my opinion). I did try a longer exposure but the milky effect didn't work. Think I'm also lucky in that the breaking wave acts as a subtle lead-in line from bottom right towards Clavell's Tower - which I wouldn't have got with milky water.
Cheers
Andy