Hi Nick,
Apart from the cost side, there's nothing wrong with the GWS products.
Like you I also saw these tubs of groundwork materials in the LHS and decided to try it. I tried the sand & gravel set. I find it works very nicely. I stuck the sand down using Woodland Scenics scenic cement (which as John points out is basically just diluted white glue). The key is to sort of sandwich the groundcover between the glue. In other words, apply glue liberally to the surface, apply the groundcover, and then apply more glue to seal the groundcover.
Over on
HFM Costas has recently done a very nice little SBS on doing snowy bases. Sure it's mainly for figures, but the techniques and principles are applicable to other genres as well. Here you go:
SBS: Snow bases for beginners HTH
Rudi
