Well, they arrived.
As it turns out, they do have branding on them. The Stellar Labs logo on the outside of the cups. After listening to them over the last week, and AB'ing them with the OneOdio's, I can say with some certainty that they were worth the money! Impressions? For those interested, I mainly have compared them to the OneOdio's.
The Stellar's are deeper; both in the detail and bass departments. Not as dark as the OneOdio's, either. I do prefer a darker sounding headphone though, but I wouldn't describe the Stellar's as sibilant or grating. Just enough treble, and I actually find them a nice complementary pair to switch between them and the OneOdio's.
The Stellar's are definitely more comfortable for longer sessions, to me. My pair of HM5's finally 'gave up the ghost' after years of faithful service (boohoo, I miss them) and I find the Stellar's give a similar feel on the head. Yes!
I'll stop before I write a whole review on these, as a lot has already been said about them. Final word if I were to choose between the two; the Stellar's for their comfort and deeper/longer/more critical listening sessions. The OneOdio's I will continue to use for when I'm going out, as they feel lighter on the head, are smaller, and have more relaxed sonic character.
Next I intend to experiment with the semi-open grille mod, as described by
@Slater