With an analog you are operating on a much broader set range than a digital. Where a digital thin walled it would never turn off, an analog has a larger cycle or wave length of operation. A digital is built to hold a temperature, an analog has no apparent exact setting, it fluctuated between two designed points. Medium may be 275-225 with the 250 being the midpoint.
Thanks, Foamheart. Not sure if it was you but someone in a thread posted that an analog thermostat is slap--something--or basically an on/on switch where it hits target temp, shuts off and comes back on again at what I think was called the control or temp set point while the digital therm is designed to maintain an even temp so it will switch on and off frequently. But now it all makes sense to me. Glad I spent the extra bucks on the digital.