I've given up growing main crop potatoes now mainly because of blight. I don't like the taste and texture of the Sarpo varieties, although if you do, they are quite blight resistant. I found it a problem when storing maincrops that, although they look fine when they're put into the sacks, inevitably there comes a time when a smell of blight becomes apparent, and now the whole sack has to be emptied out to find the culprit/culprits before they rot too many other spuds. I just buy mine a sack at a time, as and when I need them, from a local supplier and save myself the stress and the space needed to store them.
I now grow just one row of earlies, and three rows of second earlies, each row being 30' long. Everyone has their own preferences, and what works for one may not work for somebody else.