The Hakko FX-951 iron, while expensive compared to the irons many hobbyists buy, is actually good value. The key is their T15 series of tips. They are capable of delivering a lot of heat very quickly. The thermal recovery time, that is, the time from when you touch the tip to your work, to the time the tip is back up to its set temperature is very fast, even when you are soldering large metal areas. The actual heating element is built into the tip, not into the handle, and the temperature sensor is placed right behind the tip, that’s the secret.
A previous poster mentioned that his auto-turn-off feature was annoying. This feature, more accurately called a power-save or tip-saver, turns the temperature of the tip down when not in use. The timer is adjustable to 30 minutes in one minute steps, (which is the time delay from putting the iron back in its stand to where the iron is allowed to cool down), and if he had adjusted his timer to something reasonable, like 20 minutes, I’m sure it would not have been so annoying. I like this feature a lot because you can leave your station on all day and the timer will look after cooling the iron off when you don’t use it or walk away from your workbench. When you pick up the iron again after it has cooled down, or even when you have just switched it on for the first time, it only takes 12 seconds to come up to full temperature and be ready for soldering. That’s not annoying, its actually pretty neat.
Hakko stations with this technology compete with JBC and Metcal in the professional electronics market and these other brands also use similar technology in their tips. I don’t work for Hakko or have any stake in them, but after using Weller, Pace, Metcal, OK Technology, and JBC irons for over 40 years, I chose to invest my own money in Hakko because I like their performance, their feel, and their reliability.