Donation Forms - Prompt Reoccurring

I am working on my donation form using the new form generation tools.  I am unsure whether to use the Prompt Reoccurring function and if I do what parameters should I use.  What has been your experiences?  Does it work or do people seem to be turned off? What range of gifts did you use for offering this option and what % suggestions did you use?

Any insight you can offer would be much appreciated.

Faith