We used two [damaged] SONY handycam DCR-PC100s, each weighing 1 lbs 4 oz.
Attached one to a 3" VACUUM cup, and one to a SUCTION cup, and then stuck them on a vertical, melamine covered door panel.
The purpose of the test was to see how long before each would take to loose suction, and the camera to drop.
We timed the test with a stop watch.
The following picture was taken after 1 hour and 19 minutes (VACUUM cup on left, SUCTION cup on right):
First off, the VACUUM cup (on the left) held its horizontal position MUCH better than the suction cup, which tilted downwards throughout the test. The VACUUM cup on the other hand had a very firm connection, without listing any great deal.
---> The SUCTION cup lost suction and camera dropped after 1 hour and 30 minutes.
---> The VACUUM cup lasted over 100 hours!! (The stop watch stopped at 99 hours 59 minutes and 59 seconds, but suction remained for a few hours more.)
Note: a Vidled does NOT weigh as much as this camera does, and the weight is much loser to the pivot point so better results should be achieved using one VIDLED light.)
The vacuum cup is a FAR better solution, but it costs more too. The suction cup is a great value, as long as no long time suction is required. We sell both these items as accessories on our website's products' page.