I could be wrong but save for temple sacrifices, I think Orthodox Judaism is the same as OT Judaism. I read somewhere once that the reason they don't have priests anymore is because the Temple is destroyed. I think the Orthodox still abstain from pork, refrain from unecessary labor on the Sabbath, pray for the dead, observe the Law (and its 613 commandments), etc. etc.
Orthodox Judaism views itself as the continuation of the beliefs and practices of normative Judaism, as accepted by the Jewish nation at Mt. Sinai and codified in successive generations in an ongoing process that continues to this day.
http://www.pacificnet.net/~faigin/SCJ/faq/02-04.html
A Reform Jew has the right to decide whether to subscribe to this particular belief or to that particular practice.
http://rj.org/rj.shtml
So, I would say to answer your question, Reform Judaism compared to Orthodox Judaism is what Protestantism is to Catholicism, IMHO.