Cavity wall insulation?

[flobadob]

I've gotten two quotes for cavity wall insulation. One company uses white bead by Certainfill and the other company uses a product called InstaBead. The company who uses InstaBead claimed that it is the best insualtion on the market, the reason being something to do with the glue used(I didn't pick it all up). The thing is the InstaBead crowd are coming in at £200 over the company that uses Certainfill bead.

My question being is their really much difference between the two types that would warrant paying the extra £200? Basically, I would like to get the best job done for the long run.