We have got 4 quotes for a conservatory, one is using Planitherm argon filled sealled units, 2 offer Pilkington K, 1 offers Pilkington float. One Pilks salesmen said that the argon units can 'implode, argon sink to the bottom and leak out'. Is Planitherm a reliable product?

Am I right in thinking that all Planithem units are argon filled?