Mother, can we trust the NFPers?

I've recently begun to wonder whether the NFPers (Natural Family Planning types) tend to promote urban legends about oral contraception in order to discourage its use among Christians. I have mostly anecdotal evidence for this, nothing hard and fast, but it causes me a certain amount of frustration. I know that NFP people are essentially working from a philosophical position that differs from my own, but I don't want to see elements that disagree with their philosophy unfairly slandered.

WebMD lists the advantages and disadvantages of oral forms of contraception. These are specifically for those forms that contain both estrogen and progestin.

The advantages that apply to most Christians include:

• Reduced bleeding and cramping with periods, which lowers the risk of anemia
• Reduced pain during ovulation
• Reduced fibrocystic breast changes
• Reduced risk of pelvic inflammatory disease (PID)
• Reduced risk of ectopic pregnancy
• May reduce acne
• May reduce ovarian cysts
• May reduce symptoms of endometriosis
• May reduce bone density loss
• May protect against ovarian and endometrial cancer

The main disadvantages are:

• Pills must be taken every day
• May not be as effective when taken with certain medications
• May delay return of normal cycles when heavy dosage is used.
• May cause weight gain when heavy dosage is used. (thanks to Ellen for this reminder)
  
• May cost more than other methods if used for many years
• Does not protect against sexually transmitted diseases such as HIV.

I guess I basically want a level playing field if we're going to talk about these issues. No false accusations, and let's be honest about the advantages/disadvantages of both sides of this increasingly pressing debate in Christian circles.

Grace & Peace