I have an IKEA Malm desk which has an MDF core in some places but hollow cardboard in others (probably most places) so I couldn't use screws.
Surprisingly the adhesive by itself worked, at least so far. The combined weight of my headphones (Bowers & Wilkins PX, Corsair Void Pro Wireless) is however around ~730g, similar to the recommended combined weight of 700g.
The hanger itself is fine, I like the flexible rubber it uses far more than the metal used in competing products. You won't accidentally injure yourself or damage leather headrests of headphones with this rubber hanger.
However I wish they made the base where the adhesive is attached to a bit bigger. The adhesive isn't peeling from the table or anything, but the base looks so tiny compared to all the headphones mounted on it that it feels like it could fall off anyday.