There's not a whole lot in those Vallejo bottles compared to Model Master's own semi-gloss clearcoat bottles. Not to mention, rattle can last a lot longer IF you buy Rustoleum's brand semi-gloss clearcoat. I look at the perceptive of having a steady supply in rattle can or bottles.
Not to mention also, the consistency of getting the same even shine clearcoat of semi-gloss ratio between mixing gloss and flat clearcoats. I'd rather shoot straight up semi-gloss clearcoat out of a single bottle or rattle can knowing it's going to give me an even shine clearcoat as opposed to an uneven shine clearcoat.
But hey, each to his own......