Suncorp insured me for $1499 for their top cover (including lifetime new for written off vehicle). I liked that better.
Speculating here .. but in 5 years time to keep the "lifetime new for old" you'll need to keep insuring with them. They'll take advantage of this with the premium's skyrocketing .. but you'll feel compelled to stay with them to keep this 'feature'. May pay out for you in the long run.