"Can anybody compare the 800D's vs the 802D's? Is there a huge difference?"
I can not. But if it were me I would make sure my front end is top notch first if I were buying NEW. With out a good front end and B&W there is no point.
If you can get a pair used I would buy the 800D and never look back. I would not care how much better they were.... just that they are better. It would save me the thought of upgrading later. Also if you end up selling them there are a lot less 800Ds for sale so they might hold their value better over time.