Because there is no "PTO" organization, there often is no one who can speak for "PTOs." You may find a local PTo president who could speak about her/his experience as a PTO, but that can be hit or miss.
Our feature story on PTO v PTA is on this site. You may be able to make good use of its analysis in your decision.
Our brand new school started a parent group this summer. The small commitee decided to make it a PTO until we could get further input from other parents when school started. I know I can contact the PTA for a presentation, but who can we use to debate it or present for a PTO?