You won’t lose anything by just trying. Bugs that bother one user might not appear on another users machine or with different ways of working. You’ll never get a software that has all bugs fixed.
About the 7.07 update: I expect a more or less simultaneous release of 7.5.1, adressing some issues present in 7.06 and 7.5. Just can say that 7.5 works very good for me (and it seems for many others as well) with just a few minor issues, so I wouldn’t hesitate. Your Elements 6.07 install will keep intact anyway, 7 is an independent installation.
7.5.1 will be released together with 7.0.7, and it’s basically the same update. I don’t think they have specified what bugs it addresses yet. It’s possible that they will call it 7.0.2 to avoid confusion with Artist 7.5.1.