Re: Wrong answer
"With most irons, the soleplate is unevenly heated and the temperature swing as the thermostat cuts in and out is too wide."
1: Elements are generally run around the entire perimeter of the soleplate. Uneven heat is a sure sign of either a failing element or an iron so cheap and nasty it's dangerous.
2: Other than the aforementioned "cheap and nasties" I haven't seen an iron on sale with an actual mechanical thermostat in it for years (they're unreliable). Almost all of them rely on some form of thyristor and constant temperature feedback to avoid hysteresis overshoot.