The Dauntless looks enormous compared to the Protostar.
I like that Holo-Janeway keot her Protostar uniform.
It does.
It really gives us a sense of scale of these ships right next to each other.
But then again, the Protostar is quite small... onl 4 decks large - 3 decks in the saucer, and the bottom section of the secondary hull is the 4th deck which houses most of the stuff including the vehicle replicator.
The Dauntless secondary hull/neck is at least 4 decks high on its own (possibly 5)... with the saucer section adding another 10 decks it seems
All in all, the Dauntless might be larger than Voyager (or it could be same size - but lengthier).
So, we're looking at almost (if not exactly) 4x the size differential in favour of the Dauntless compared to the Protostar.
EDIT:
I think I may have to revise my original estimates of the real Dauntless size vs the fake one.
The fake one had 7 decks it seems.
I found some diagrams which show internal deck layout, and the saucer apparently has 7 decks, but the secondary hull has a few more - about 2 or decks - but I wouldn't be surprised if SF increased its own Dauntless size to be larger than that.
The exterior seems to suggest something the size of the Intrepid class from what I saw in the promo.
Ah, we'll see.