"ease of handling and maintenance"
Compared to EE Lightning. Maybe.
"can lift a heavy load"
FOR YOU
"of rockets, bombs, and other under-wing missiles"
Would like to see how to fit the avionics for firing anything more complex than a Sidewinder after installing radar and all the gear needed for carrier ops in the age before microprocessors. OK, G.91 could fire AS-20's, but it was two metres longer and a ton heavier to begin with.
Don't get me wrong, Gnat was a great lightweight dogfighter, but Folland's marketing department in that leaflet sounds like having delusions of grandeur.