The first is unbeatable. Masters of Metal, Agents Of Steel is their Hymn. I like their later works also, Agent Steel can do no wrong IMO, don't heard their new album though, is it good or are "Nu-metal/Start-Stop-riffs" taking over?
Haven't heard the new one, but Omega Conspiracy was pretty decent thrash metal. Which indeed was never what Agent Steel was about. Good band still, but I think they should chose another name. I am friendly towards bands changing members when needed, but replacing John Cyriis in AS is like replacing Tony Iommi in Black Sabbath.