"Used with a 3.2J drill. Costs 3x as much as a bog-standard, but thought I'd give it a punt. Battered through accringtons with no problem, allowed drilling very close to edge without bursting. Most impressive was drilling through common clays, taking 8-10 seconds to go through both leaves of a cavity wall. Dust clearance is excellent, even with a polyurethane foam cavity fill (so dust had to come out full depth, not into cavity) the dust was literally ejected from the hole like a fountain. Not sure on longevity, but will prob be no worse than any other drill, maybe better as their seems to be more clearance behind cutting blades which will reduce rubbing/wear. Worth the money."