The conversion to a convertible didn't hurt the F430 one bit. Chassis rigidity remained very similar, and performance was only slightly decreased. The folding soft top roof was full automatic, that folded away under the engine cover.
The 430 featured some nice tech from the world of Ferraris Formula 1 team. Such as the electronic differential, which greatly improved traction and road holding. The body also benefited with extensive usage of aerodynamic simulations, which helped to fine tune the body work of the Spider to make it more efficient.