RE: the Radio Replies series.
While these are my absolute favorites in real answers to real questions... Obi Wan pointed out to me that they are slightly dated in church law. They are dead on track for doctrine... but some other disciplinary things might be incorrect now.
That is true and should be kept in mind lest you become a SSPX.
The Doctrine cotained is extraodirnay and the best Q and A set out there but I would say 10 percent of the stuff there has changed mostly disciplianry things, women covering thier heads in church, Cremation, married men becoming priest - we now have married priest through a dispensation for protestnat clergy so its not as absolute as in the book and now we have married deacons as well, why only latin mass must be used in the Latin Rite, why the dietary laws for every Friday must be kept this is no longer the case except for Lent other Fridays we can choose another penance. Etc Etc. Since Vatican 2 we have a softened stance on the death penalty not presented here. Also the ecunemical stance of the church has softened in language since this book was written.
There is similar book series out there that is nearly as good and very much updated to Vatican 2 and contains modern questions not asked in the Radio Reply days, Such as Stem Cell Research, Viagra, Pope Pius XII controversy, Rapture, Sex Education, Cremation, Holy Laughter, Kwanzaa, , Sex Edcucation, Organ Transplants, Third Secret of Fatima, Clergy Sex Abuse, New Age, Women Priests, Birth Control, and a different take on evolution and the death penalty. This Set has 2 books its called Catholic Replies 1 and 2 but its not as comprehensive on dogma as the Radio Replies so I wouldn't throw away those books for this newer series but would get the newer series for the better reference on church law in regards to customs that can be changed and have been changed since Vatican 2. Keep the Radio Replies for the hard hitting reference in regards to dogma. So my suggestion is to buy both. Both series covers enough things that the other series does not that their is unique value in each set even though there is some overlap. I think one would be suprised of just how much the Radio Replies stuff still aplies for today. Frankly I think they should come up with the same edition but the Q and A stuff that is in contradiction to Vatican 2 edited to conform to modern church teaching or else this book might become a weapon for SSPX and Sedevanctist.