I had a job that required about 200 holes to be drilled and i bought this for one of my core drills, for another core drill i had a core drill, i drilled this stadea about 100 holes 12" deep and 5" diameter. On a stone retaining wall I was honestly impressed never thought I would last 50+ holes would definitely buy again One thing I often see in these bad reviews is people use the wrong tools for the job and then something blame, see people using regular drill bits, hole drill bits, SDS plus drill bits that aren't designed for this type of work, I use this on my Milwaukee bit with a constant water supply that pours water INSIDE the drill, not outside like me saw. some pics of people spraying it with a garden hose people need to understand that these bits are for real world use. Reaming, not a normal drill