For the DGC-6805 vs DGC-7845. I think the biggest difference would be avalibility of spare parts for servicing. At least in the EU, the manufaturer has to provide parts for 10 years after the end of sales date.

Other differences would be:

- Updated exterior ”design language”.

- Updated / modernized / sharper looking M-Touch UI screens.

- An additional status light indicator and sensor on the front panel.

- Updated electronics for the ”Smart Phone” M-Touch control embedded in the front panel.

- Looking at the parts manual, the inside layout looks the similar between generations.

- They removed the bottle of DGC clean shipped with the unit. (at least in the UK, they did)

Miele 6xxx ovens don't appear on the Miele USA website. Miele 2xxx and 7xxx ovens appear. More money appears to buy more features. The H 2780 BP is $4300 while the "top-of-the-line" H 7780 BP is $7800 with H 7180 BP and H 7580 BP in between. I'd look through the features/specs of each oven to decide among them (e.g., is it worth +$1300 for a wireless probe?). Do they cook any different? Hard to know.

CR did test the older Miele H 6281 which was a so-so performer.