Well, I think "bolder" ES7 is a nice way to put it, but still... not quite.
The ES10 is... a lot more satisfying to me than ES7. I think it's closer to a "even more enhanced, more detailed" ESW9 to me than something that grew from the ES7. I haven't heard ESW10, so I can't really comment, but... I can definitely feel the similarities between ES10 and ESW9.
My general impression of the ES10 is that it "borrowed" the warmth of the ESW9, and some (not all) of the liquid smooth midrange. It didn't try to cover up flaws like the ESW9. Instead, it revealed more and showed off more. Then it brought on its own signature of bass, added some details and sparkles, and laid them all out in front like a meticulously sculpted work of art.
What I found amazing, though, was that somehow, the ES10 knew exactly when to channel its energy. It doesn't peak like my other brighter headphones. As a result, I can enjoy listening at high volume without sibilance. But it still doesn't sound veiled. I can't quite put my finger on it, but it sounds like 8K to 10K response oscillates between (revealing) and (suppressing) depending on the track. It does miss sometimes and make some tracks sound overly dark, but it has never let any sibilance pass.
They're not exactly bright, but not exactly dark, in other words. I think the apt description is more that... they are just bright enough and dark enough.