Do higher wattage irons just heat up more quickly and retain it better, or are there other advantages?
The workpiece sucks energy out of your iron. You need enough power input to achieve flow temperature at the joint, so larger (0r more thermally conductive) workpieces need a higher power iron.
soldering
Do higher wattage irons just heat up more quickly and retain it better, or are there other advantages?
I'll be soft soldering with a lead-free solder.