I agree that the fast blink attracts more attention, but I also assume most idiots on the road are blind, based upon the evidence of their driving habits.
When possible I try to avoid fast blink signals as this indicates one of two things:
1. You have a signal light out
2. You have modified your signals
Around here, either of these is as bad as using an arm signal within view of a
cop. It attracts their attention. Then, they pull you over for no valid reason, demonstrate their lack of understanding of the signal light laws, harass the sh!t out of you because whatever you are riding/driving isn't what they feel is appropriate for your age, and make your life
H3LL next time you try to cross the boarder. Not that I have first hand experience there or anything...
So, both flash speeds have merit, but you want to think of the consequences. I certainly do on my Z1000 with it's mods including fast-flash, regardless of how I'm riding.