Are the newer public key methods better than RSA?
Diffie-Hellman (DH) is actually older and simpler than RSA, and along with DSA it can be used for all the things that RSA is commonly used for. The differences are minor and technical. Elliptic curve cryptosystems (ECC) have the advantage of shorter public keys. The best attacks on ECC are exponential in the keysize, while the attacks on RSA and DH/DSA are sub-exponential, so ECC will become more attractive after a few more years of Moore’s law. Other methods like NTRU have not yet gained credibility.
