I chose to stay with Seiichi and Keiko on our final night in Japan - the third stay in a month. Seichi kindly printed me out an itinerary of which trains I should catch to get to the airport on time and it worked beautifully. (They're very handy for Narita)
So after three and a half weeks of futons, I can unreservedly vouch that Seiichi and Keiko's futons are the most comfortable ones in Japan. :)