In my case it was how big the "V" was where the lapels met - some jackets have the lapels crossing much higher up the chest than others and my preference is to show more of the shirt and tie. E.g. vs My preference is for the latter. Both are valid but you need to understand what you yourself like.
Thanks, Stitchy! It gets addictive but really, once it's done, the maintenance is pretty easy. Thanks! 'Lived in' beats the alternative You definitely should. The right DB makes all the difference and you need to understand what you like in terms of the style.