Dundee sharp is subjective to a lot of factors hone grit and experience are the two main ones as i see it,if you can't afford a higher grit stone i would look into getting some diamond or cro ox paste for the back of your strop or any other flat surface,it will refine and polish a 4k edge quite well and make do until you get more stones,stepping to your 4k sooner than usual will take longer but that time will polish more of the courser stone scratches out but if you really want sharper and smoother you need the higher grit stones,now to explore the different degrees of sharpness finer stones are needed and you need to sharpen test then repeat until you get to the over sharpened edge,the finer the stone the more you can push it to get the experience as once you know the difference in different degrees of sharpness you know what it feels like