I'm not looking to jump into Mythic right away obviously, but my Mage is 685 at the moment although only has a 640 ring. How much would a 640 Legendary ring hold me back in raids and would raids even take in people at this point who are so far behind in their legendary rings? The "catch up" mechanic or buff that they put in hardly makes a difference so it would be at least 2 months before I could even get my 715 ring.