Ironically, guess who has shaped me a board after telling them I was after something like the hypto krypto

To answer the poster, I would definately grab a hypto - like shape first rather than the sweet potato. It is much more of an all rounder and can hold itself in bigger waves (think pumping down south on a 5'8 - no chance naming my 'secret spots'

). That pin tail is the goods and the extra volume really helps you get into waves earlier. I find though that while adequate for smaller waves, it really comes to life when things get bigger (think OH).
To Bman, if you do go for it, you won't be disappointed. I got mine additionally as a quad and the speed you get off it, it just flies! Ironically, switched it over to a thruster and it held much better in the bigger stuff (good if you weren't after the speed but getting the turns going). Dave at Katana really looked after me and the crew there are great people. I will be seeing him again definately for my next board!