For stability, just avoid these extreme pulled in nose shapes.
Some width in the nose will make wonders for the stability, and thus allow to keep a somewhat narrower main width and/or thinner rails for rail to rail action on the wave.

Things like the Infinity RnB, Portal Phantom, Jimmy Lewis Super Frank or Destroyer, Gong Karmen, the new Starboards...

Fisher Grant even placed 2nd at the recent Carolina cup, in both the longboard & shortboard divisions, with a Phantom with a comfy nose:

The Mad Dog will be more stable as it has a wider tail, It's the tail that makes a board stable as you are constantly moving from the center of the board to the rear, A Narrow tail will want to sink as soon as you move out of the sweet spot, so if your not used to it especially in choppy conditions it can wear you out pretty quickly.

DAZZAINTHEBAZZA said..
The Mad Dog will be more stable as it has a wider tail, It's the tail that makes a board stable as you are constantly moving from the center of the board to the rear, A Narrow tail will want to sink as soon as you move out of the sweet spot, so if your not used to it especially in choppy conditions it can wear you out pretty quickly.

Not necessarily... I had a 8'1 Maddog, they have bulk rocker and the heavy vee runs almost nose to tail. Both these things made the stability quite tricky for a board with its generous dims, it seemed with the vee it always wanted to be on one flat or the other. Absolutely wicked on a wave though.

Awsome guys thanks for the feed back.
Cheers