Now that's a good question.
Comparing IEMs to over-ear headphones can be a little bit of an apples and oranges things, and I haven't seen the measurements for the Vega and Dorado yet (I'll sure they'll be coming soon), but I wouldn't be surprised if the Vega curve looks pretty similar to the Cascade. I'd say that the Vega has similar subbass extension, a smaller mid-bass boost, and slightly more recessed mids with a similar treble bump as compared to the Cascade. I don't really hear that same sort of "dark" sound as the Cascade though with the Vega and definitely not with the Dorado.
That's good to hear re: the darkness! That's something I like to hear and realized recently about my personal preferences.
Looking forward to reviews to seeing more impressions from the community at large. The Bloom pieces on both were great first tastes however!