how do they compare, and are they as similar as they seem?

Thinking about replacing my 5'8 spit and 6'2 alt into a 5'11 Chub or 6'0 SubS.... I think I'll be happy in the spitfire wave range, but will I be able to use it in the same conditions as my alternator?

A lot of boards seems to come with 5-fin option now a days... why not the Chub and SubS? Does those models not work good as a quad?