I wish the primaries were much closer together. By the time it was my state’s turn to vote, it was all over. Have them in a week and don’t declare a winner until the last vote is counted.
But that's precisely the problem ... if you mash them all into one week, you encourage the candidates to go for style over substance. It's a great way to pick terrible candidates, with no time to assess their relative qualities over time.
I would much prefer that the primary season be stretched out significantly, with the order being selected such that it's impossible to gain a majority of delegates before June.
The weak sisters would drop out as the early primaries came out badly for them; and by June you'd be left with the truly viable candidates.
If one could somehow inject real debates into the process, on real issues, that would be swell, too. The real red-meat debates would begin in May, once all of the poor candidates had left the stage.