First off Make sure your skis are ground flat, sometimes companies don't put as much attention to overall quality of freeride/freestyle skis. A lot of times the bases are either base high, or edge high, concave, convex, sometimes both. This can create unwanted drag and friction, as well as make your glide unpredictable and edges hooky or slippy. Even a lot of race skis from the factory need some work to get to flat.
Better quality waxing irons do maintain a more constant temp, than your avg household iron, partly because of the digital controllers on the nicer one can maintain a more accurate temp, also the thickness of the metal is quite a bit thicker which will maintain constant heat better than thinner metal. That is one of the biggest differences in the low end vs high end swix irons.
The high end have a digital controller and a super thick metal plate that won't distort temps much when dripping or spreading. The lower end thinner metal and an anolog/dial temp control.
As those have already said, it is fairly critical for maximum saturation and to preserve the molecule structure to have a fairly accurate iron temp.
As important if not more important is selecting the best wax for the conditions based on temp and humidity/moisture level.
Also cleaning dirty bases can improve your glide a ton. A lot of dirt and oil gets stuck in the base and can give off an attractive charge to the dirt in the snow slowing you don a ton.
Just like anything else in life you get out of it what you put into it.
I really enjoy having a predictable smooth glide every time. It is worth the extra time and care to get your boards juiced in the morning or the night before.