Originally Posted by MAD_HATTER
for the first time users.. sometimes they don't get it right the first times because they dont put the foil tight enough
Yep, and with the three funnels I have used, one spire (hole in the middle) was raised too level with the rim of the bowl which had a negative impact on airflow. I have yet to see this defect on vortex bowls. Probably because they are mass manufactured in China by machine. Maybe I'm wrong about that, but consistent none the less.