FF for $1500 is very tempting. I just invested in t3i, kit lens and sigma 30mm. May be it is true early to get rid of them and move to FF. I need to learn about raw shooting first.
It's not any harder to learn on a 6D, and raw files are just files that don't have all the settings applied to them yet (white balance, how the image is rendered, etc.), when you import into something like Lightroom you can apply the default "Camera Standard, Portrait" etc. and more or less have jpeg like-output, or you can tweak.
They're both very capable cameras, and the T3i can also product fantastic images. The 6D will have better low-light abilities though.