I used one for ages. Pros: no hormones. Don't need to do anything daily. Can't feel it (either partner) once it's in place. Relatively easy to use (once you get the hang of putting it in and taking it out.) Comparable to condoms in effectiveness.
Cons: It's only about as effective as condoms, which is to say not as effective as the pill or some other methods of bc. If you are prone to bladder infections it can contribute to them- I would get them before I realized I needed to wash the diaphgragm again before inserting it, then go pee immediately afterwards. This is contrary to the package instructions that say to pee first, then insert.
I did like it as a bc method- the only reason I stopped using it was because the spermicide you need to use with it stopped being sold in Canada and the alternative spermicide was SO expensive. And because we're done having kids now, the failure rate felt a bit high for me.
at 5:10 PM on Feb. 19, 2010