I've been trying to get friends interested in this, but with no success. I don't think anyone trusts it as a gaming medium. My local toy store was selling it for $8aus a kilo, so I ended up buying 5 kilos. It sits quite nicely when moulded, sits in place for hours, and doesn't catch on the miniatures as they move around the surface - i.e it's nice and clean while playing on it, and for cleaning up afterwards.
I guess the main problem is that you're limited to 'desert' type games...
One of the advantages, though, is that you can plonk figures/vehicles 'into' the hills etc, and not worry about them slipping off...
I reckon if I had ten kilos in total, I'd have enough for a 4ft by 4ft table...
Like I said, none of my mates are interested. Having said that, my mate has an awesome sand-table - so why change to something new?