I recently upgraded from a 30D to a 6D and gave up a 10-22 and 17-55 for it. Full frame is nice but it won't make your pictures magically better. That's all just fluff. The usefulness of shallower DoF is overblown as well. However, it is much easier to post process photos on a 6D due to improved dynamic range, less noise, and a better noise profile generally. You can pull back highlights and push shadows without worrying about degrading image quality too much. The larger viewfinder is also a big plus for me, especially when equipped with a precision focusing screen. It is genuinely easy to manually focus, whereas on the 30D it was hit and miss at best. I don't imagine a 70D would be better than the 30D in this respect.
Needless to say, the 6Ds high ISO performance is exceptional. ISO 12800 is cleaner than ISO 3200 on the 30D. ISO 25600 and 51200 aren't too bad with some aggressive noise reduction. In all honesty, if you have some decent fast glass, you'll be hard pushed to find situation where ISO 25600 and 51200 are actually necessary anyway. I would be surprised if the 70D was as capable as the 6D in this category.
As for lenses, the 10-22 was a hard one to give up. In my opinion, there aren't any wide lenses for full frame that are as good as the 10-22 without spending $$$$ on the 16-35. The 24-105 is a pretty good substitute for the 17-55 f/2.8 though. What I have found is that a lot of the primes start to make more sense on full frame. I bought the Sigma 35 f1.4 which is a lovely field of view and it hasn't come off my camera since. 50mm and 85mm aren't bad either.
I think that if you shoot a lot of sports or wildlife, or shoot exclusively in JPEG, then you'd probably be better off with the 70D. If you shoot RAW, prefer wide photography, portrait, or low light photography, the 6D is a clear winner.