It's getting to be like the difference between a blue sedan or a red convertible - often a matter of personal choice rather than engineering.
We purchased our CYV based on preferred location, and it just happened to be frame. After living in FL for a couple-decades-plus, block construction didn't seem that important anymore.
The construction standards have radically changed in the Post-Hurricane-Andrew age, mainly due to mandates from the insurance industry. These changes have really made a difference in both house stability and cost (higher now), and a walk-through any unit during various construction phases will bear that out.
These are a couple of web sites with information about the FL Building Code. They have the technical information for anyone with concerns about construction standards.
http://www2.iccsafe.org/states/2004_...FL_%20Bldg.pdf
http://www.floridabuilding.org/c/default.aspx
Hope this helps...