OK, I don't know if I'm even qualified to reply to this thread, because the common theme here is that you can get away with the cheapest iron you can plug into your socket. Since I just splurged on the Toko T14 from Alpinord, I think I'm automatically disqualified. Nonetheless, I'm going to weigh in with my totally biased personal opinion.
Years ago, I used a Norelco, which I somehow misappropriated from my wife. It worked. A couple of years ago I upgraded to the ubiquitous green Wintersteiger (also available under a number of other brands) model. I think I paid about $30 at end-of-season sale. At $30, it was definitely worth it. Not in the sense that my skis were faster, but it was more comfortable to use, due to shape/size, time to heat up and the tighter temperature control. Bottom line, if the missus gives you an old household iron, your decision has been made for you. But if you're trying to decide between buying a new clothes iron and a ski iron, go with the ski iron. The price difference is minimal, and the wax iron will work better.
Now, enter the other extreme, top of the line wax iron, a digital one - who needs a digital wax iron? Maybe WC technicians do. Maybe. Most likely, they don't. They probably have a 15-year old iron which the can set by touch to the exact temperature they want. Honestly, I don't need one. It's not going to make me competitive with WC skiers. I don't even think it's going to make me competitive with my old self from the pre-digital era. I doubt it makes a significant difference in the end result, but it's a breeze to use. It adjusts to the new temperature setting extremely fast, and stays there within a very narrow margin. Also, it is just a very good wax iron. The grooves in the sole plate distribute the wax very efficiently, much easier than my old Wintersteiger.
I think of this the same as about getting up to the mountains. I can get there in a Chevy or in a BMW.
Neither is going to make me a better skier. Judging by the nuber of BMWs in the parking lot of any resort, the fun-factor wins over the cost-factor very frequently.