D5100 to D800/e

Any D5100 owner upgrade to a D800/D800e? What are your opinions now that you both (or now that you've upgraded)? Is it worth the price of admission?

I already have a couple of FX lenses so I'm ready to upgrade :).

I have lightroom 3.x. Will I be able to use it for the D800/D800e raw files or do I need to upgrade to LR 4.x and upgrade the raw component?

Thanks,
Gary