If you pull the crown, the drain on the battery is less because the tiny motor(s) that drives the hands no longer operates. It leaves only the chip current to drain the battery. The price of batteries being what it is, the cost advantage is moot.
Originally Posted by
Ronda
Power saving mechanism (pull stem out): Reduction of consumption approximately 70%
Quote is from their 715 movement data.
AFIK, the stem on most watches remains sealed at least partially when the crown is pulled. But even so, condensation needs moist air to somehow get into the watch case and then quite a temperature drop to actually cause internal condensation. Most watches of any worth are not stored under such conditions.
My workbench is in my garage where the humidity is normally above 85% and the temperature swings 20 to 30 degs F between day and night. I have never seen condensation on any watches in there or any brought into the air-conditioned house either.
I won't bore you with how condensation occurs, but my though is that watch cases are small relative to vehicles which do show some external condensation (but rarely internal) when the humidity is really high. With a large metal object and therefore a high thermal capacity, the surface temperature lags significantly behind that of the atmosphere as night turns to day.
cheers,