Although I am not specifically a relic hunter, I would set mine just like I do for coins. All metal and ignore the stuff (via tones and TID) that I don't want. My suggestion would be to take some "samples" of relics you have found, pass them under the coil and take note of the sound and TID of the "keepers". For information on setting the Noise Cancel, Sensitivity, GB etc, go to the FAQFAQ listing at the top of this forum and find the one for X-70. In addition, there are lots of good posts to this forum, from lots of knowlegeable folks. Just do a search for the topic you are wanting to learn more about. And, if you have any specific questions, don't hesitate to ask.
The X-70 will hunt very similarly to the X-50. However, I really like the narrower notch segments and Threshold tone offered by the X-70. And, I can't deny that I find the Auto GB, Auto NC and Prospecting mode (for target sizing) very useful as well. HH Randy