For what it is worth, I've had the Z3100 in a variety of use modes: daily for weeks at a time, one print per week with the power left on, leaving the power off for a few days at a time and powering up only for an occasional print or two, and leaving it shut down during multi-week absences followed by a flurry of printing. The machine seemed to perform just fine and in a consistent manner regardless of the power on/off situation. This treatment is not exactly what the manual recommends, but so far, I haven't discovered any problems over the past 18 months.
Rick