I really like my HD 8. Moving up from the HD 7 (2014), I was surprised what a difference that inch makes. It's thinner, too, which feels nicer when holding it. I got the Reader's Edition so I wasn't able to choose color but it's in that nice leather case so I'm not complaining. I smell it often.
I've read quite a bit on it, mostly using Aldiko Premium, but also the Amazon app. Haven't watched much video on it yet, but when I go to Florida in May to visit my mom, it'll get a work out. That's when my HD 7 got the most video / music use.
I think the feature that will make the most difference to me in the long run is the SD slot. I still need to get a bigger mSD card before my trip, but it's really nice to not have to worry so much about the space my multimedia content takes up.