I just wanted to share my experience in the hope it saves someone else from making the same mistake.  
I bought a set of Van der Wall grips for my brand-new Walden Magic Tuflite longboard (worth over €1,100), thinking they would be a good alternative to traditional wax. Unfortunately, in my experience, they had nowhere near the grip of normal surf wax. I’d estimate they offered about a third of the traction, and I never felt secure on the board using them.  
When I decided to remove them, things got even worse. Despite taking my time, being as careful as possible and removing them exactly how the brand specifies, the grips damaged the surface and finish of my brand-new board in multiple places. That alone was bad enough.  
I contacted Van der Waal and was told to return the grips for a full refund. I paid the return postage myself and sent them back. That was a few months ago now. Since then I’ve received no refund and no meaningful response about either the refund or the damage to my board.  
For me, the biggest disappointment wasn’t just the product—it was the complete lack of after-sales support.  
I’m posting this because I genuinely don’t want other surfers to end up in the same position. If you’re thinking about replacing wax with Van der Waal grips, I’d urge you to think very carefully and do plenty of research first. Based on my experience, I wouldn’t put this product anywhere near another surfboard.  
I’d be interested to hear if anyone else has had a similar experience, or if mine is an isolated case.

Warning to anyone considering Van der Waal grips instead of surf wax.