[Seaside] CSS style - static vs dynamic

[Squeaker]

Greetings,

I have read on the Seaside tutorial that #style > should return static 
(not generated) string literals containing snippets of CSS

I have experimented with returning a dynamic string, generated at 
runtime, and things appear to work.

I know that one disadvantage is that using the css with the halos will 
over-write my #style method but this is a tradeoff I am willing to live 
with.

My question: What is the problem with generating the style string on the 
fly?

Thanks,
Frank