If you've never tried a forstner bit to drill large holes, you should. Compared to a hole saw, that thing is a monster. You have to have the right drill bit for the job (big) and the right angle of attack (straight) but one thing will work, it won't stop until it goes through the stuff you throw at it. Never again be dependent on movement and fatigue. Simply align, press and hold. In particular, this forced FAST to work with multiple supports for pipelines. The investment in a hole saw is really worth it. The adjustable tip is also practical, as every job is a little different. I really can't say anything bad about it.