sustanon eod would be less stable than enanthate or cypionate eod.
I see absolutely no reason to choose sustanon over enanthate or cypionate in any scenario unless than sustanon is cheaper mg for mg than the enanthate or cypionate products.
Most UG sustanon are not four esters, they are two esters, the shortest and longest ones the have elisted. For example, you might buy a 'prop, pp, cyp, deca' sust, but only get 'prop,deca'... the mg will be the same (still 250 total) BUT they will just go half and half prop and deca. Because nobody is going to be able to notice the difference between those two products and its going to be so much cheaper and easier to produce a prop, deca sust than to produce a prop,pp,cyp,deca sust.