For what its worth. I just put 8 new wellman 70's in my M1009 because its getting colder, and I haven't changed them since I've owned it. The P.O. put in a pushbutton bypass, and I could start the truck with ease after holding the button 12 seconds with the old plugs. After installing the wellman 70's it takes 20-25 seconds of heat time to get bring it up to the temp it needs to be at. It still fires right up after the 20 seconds, but its unnerving to hold the button that long - i feel like I'm frying them.
I went and looked at the old plugs and they are DRX00050's.
I then hooked up both plugs to a 12v power source and the DRX00050's heated up twice as fast. Additionally, when they were in the truck, they made my voltmeter jump a lot more when I hit the push button. The new plugs don't do much.
haven't decided whether or not I'm going to put the DRX00050's back in, try some AC 60gs, or just deal with the 20 second warm up time this winter.