Obviously it would be less expensive to just buy an E8000 display, but if you have an E7000, it is easy to use a Garmin 830 or 1030 as a display, and it will collect all kinds of data for you as well. You just leave the E7000 on the bars and use it when you don't have your Garmin.
If you have an E8000, you have to spend $100 on the Di2 bluetooth dongle, and remove the E8000 to use a Garmin. Dumb.
I prefer the E8000 display also. But I'd recommend sticking with the SW-E7000-L switch instead of the SW-E8000-L switch. Smaller, lighter, less vulnerable to damage and dirt/grit, and more natural to use.
That's the winning combo! Enjoy. The only other downer with the SC-E8000 display (at present - should be fixable with software update) is that if you use something like a Garmin watch or GPS linked to your eBike, you lose some functionality with the E8000 display.
Meh, I don’t track anything except for maybe how many beers I’ve drank after an epic day of riding. I’ll live with the 7000 display, not as bad as I thought it was going to be. I see you’re in PA? I’ve got a lot of homies that ride Central NY. I’m in SC, where it’s year around! Love it.