good question and personally i cannot answer, but it is very much so tip depentant, everyone comes to their own conclusion about what tip works best for them. i remember with the se535 i used to own, it was more of a matter of just getting the right size, the w4 not so much, its not just size, but also the design of the tip that effects the sound signature. for better or worse, so you gotta go through a bit of tips that give you that sound signature you are looking for.
but the #1 thing i found with tips and the w4 is the flange opening is extremely important. like i said the star tips would have been great if the tip of the opening was flared out. instead its too narrow too small, it doesnt allow for wide soundstage, it muffle the highs and mids, lows i dont feel are really that effect by the star tips, but it seems like it collapses the soundstage and drowns out or veil the mids and highs....its a real shame imo