larger sanding block systems

[Anatol]

We've always used abranet blocks, and while they go up to a 420mm block for hand sanding, they're very rigid, and the option of larger blocks wouldn't hurt.

So we're looking to get in a flexible block sanding system for larger and curved panel work - the choice seems to be between the durablock system, the k-block system, and the AFS system - has anyone any experience of these and how they compare between them?

Thanks in advance,

Tol