I have a 650DL and took a ride on the 800DE. There is no comparison, the 800 is a completely different bike and very good at what it does. I only rode it on roads but I can tell you it's quick, handles well, the brakes are very good and on the half hour ride I had, it was very comfortable.
I don't think the spoked, tubed wheels/tyres are a idea and I also thought it is expensive. I would guess that when the road version hits the dealers the price of the DL will drop like a stone so second hand ones will loose their owners heaps of money but be good buy's for tight people like me. If I was to buy a DL it would definitely be a used one with lots of kit fitted and low miles and full service history. My guess is that there will be lots of them on the market.
I'm not a dealer of expert on marketing, this is just my opinion and yes, I think the 800DL is excellent.
