I don't know why so many people have an aversion to a pushbutton glowplug system. Not much different than a manual choke on a carb, or the manual fuel switching valve setup some people use. You are in control. You determine the time the glowplugs are on. I have even tried cranking it and then holding the button for the glowplugs in at the same time. You can hear the starter slow a little bit and then it fires right off.
<_< So... I'm probably the first one to talk about having my own manual glow plug system. I've had it on my tan '88 for like the last 5 years. I've tweaked it, I added a 9th glow plug in the cab for an indicator, and it worked pretty nicely - Hold until I see a red glow, then crank.
When that truck went down on me on Black Friday(and I wasn't going to pull the motor until spring), I bought the '93 in my avatar for $1900. It came with the first /properly working/ glow plug system I've seen yet. As long as all 8 glow plugs are intact, it works /far/ better than my manual system ever did. Just wait for the light to go out, crank. It fires off within about 2-3 revs, even at 20F. It /does not smoke/ after starting.
When one GP died just after I got it, it still worked. It didn't glow as long, and usually required two cycling of the key and perhaps 15 seconds of cranking. It also sounded retarded for the first 30 seconds after starting, and I got white smoke out, etc. Replaced that dead glow plug and... starts perfectly again.
So, at this point, I'm convinced that a pushbutton glow plug system works(probably better if you use Beru plugs which can handle constant current and you can let them get really hot), but I really like the afterglow feature and the lack of smoke of a /good working/ automatic system.