Ive got an Antex one, i'd say i bought it........6/7????? years ago, ive put one new tip on it, and thats it, that thing has had A LOT of use, not even a big one either and its excellent, i had another gas one before and that was FUCKINGGGGGG SHIT.

My mains soldering iron is antex too, i reckon ive had that 10+ years, never changed the tip ever, still like new and that thing has had ridiculous amounts of use including being left one for weeks at a time