I've seen ethanol wars, engine oil wars and brand wars. This thread is a new one for me: preheat wars.
One thing that is curious to me and that's our JD 410j TLB. It doesn't have a heater of any kind. No glow plugs and no intake heater. As far as I know its just compression. That darned thing will growl but pop off in the coldest of temps. It's not even that noisey once it starts. It's pretty amazing as other stuff, gas or diesel, really complains under the same conditions. I've pondered but never looked into a heater of any sort because the critter is never near an outlet and past extension cord range. I run 10w-30 Mobile1 in everything year around but we are in a moderate climate with ~5f being the coldest. I hate cold starting stuff in that weather, preheat or not.
So for me you do what works for you, where you are and under the conditions. To me, if the machine won't start then take a hint and go back inside (wink).