So why now have Stern changed their flipper design, coils etc ?

Have they changed their flipper design??

Stern have had the single winding for some time now. Its easy to assume that when we get change its because we have a more developed product and obviously its changed for the better. problem is that this is not always true.. cost to produce will always override most  decisions.
At some point Stern realised that if they made a single winding holding coil, pulsed it electronically in an attempt to cool, they would save say $1... go make some 3000 machines and you have saved $3000 in production. Don't get me wrong, pinball has always been like this.. cost predicts game. That's why a lot of collectors prefer single player GOTTLIEBS.. each machine is given X amount of dollars to produce.. add another 1 or 3 score reels and cost comes away from gameplay design, artwork etc.
If Sterns games are playing like crap after 3 months onsite, then obviously, something is amiss. But.. Sterns main market now comes from HUO and enthusiasts being enthusiasts.. they maintain the things themselves!
So does  the main focus on a coil manufacture be for the home use over a year or two or operator sited for 3 months... is the operator going to repeat buy or is the collector?