Does anyone know if this true?

High gain smaller aerial >> http://www.trademe.co.nz/Browse/Listing.aspx?id=361028526

91 Element aerial (more expensive) >> http://www.trademe.co.nz/Browse/Listing.aspx?id=361752070
Any info on aerial performance would be good, also things like susceptibility to corrosion would also be great if you know.
Thanks