I find Dr. Janet Smith's treatises on contraception counterproductive. I was unfamiliar with her prior to FR, but have since seen her on EWTN.
Even if she believes NFP is only for the gravest of circumstances, she seems to go way overboard on her severity of contracepting married couples, particularly those who use barrier methods only. I think the ONLY argument a person can make that NFP is better than condoms (for married couples) has to include God, if not our Catholic faith. If it doesn't, the argument is disingenuous and will ultimately fail to convince.
We've all known plenty of good, holy, married Protestants who find nothing wrong with condoms. And that is because their faith has not forbidden it.
Maybe my problem with Dr. Smith is that to me, NFP really is just Catholic birth control, but I find myself wondering what world Dr. Smith lives in.
I have seen her speak on this subject in person, and have discussed it at length with her over a dinner several years ago.
I think her perspective is refreshing and essential in our age. Please take the time to read her various books on the subject. I think you will come away much edified by the effort.