I've got 5 boards with a new 17' Naish Glide arriving on the 17th October - yahoo !
Whopper V Mana.
If I'm surfing the beach breaks around me, I'll usually go for the Whopper as it's more stable and allows me to 'surf' rather than fight wave refraction, chop, ruffled surface conditions etc, you can just get out there and do it.
If I'm surfing quality waves, glassy conditions, point breaks etc, the Mana is the 'go to' board as it is definately more performance orientated than the Whopper even with the square tail.....rails more parallel, hard edged and without the big nose area of the Whopper.
I can compare it to driving a car by saying I'd go for comfort in traffic (Whopper in less ideal conditions) and a 6 speed performance vehicle on the open road where you lose comfort but appreciate the added performance (Mana in good surf).
I have them both as I surf both conditions and to have the choice is good.