I have used mine for a month or so and really like it. No problems at all with suction cups not holding. It has stayed in place for at least a week. I agree that it is a bit limited with wide angle or if taking a shot that is not perpendicular to the glass. I have left the camera/tripod in place for days to catch different shots, sunrise, sunset, etc.
What is the issue with super gluing the suction cups to the fabric?