Switch to Nikon: worth it?

Used to use 20D, 5D, etc. When the 5DII came out, I was so disappointed and switched to Nikon D700. But if the 5DIII was available, I won't. The 5DIII seems a winner on High ISO, and the controls are much improved (like the 7D). So, the gap between the 5DIII and D800 is not significant enough to make the jump.

Nikon still has better AE and flash system, and good 14-24, 24-70 lenses. But Nikon's products are generally cost more than Canon's.

If I were you, I will take the 5DIII and be happy. But I am NOT a pro, all these cameras provide more then I need.