Re: NX class and the Akira Class
In a Mirror Darkly showed that in-universe-wise the sleek Constitution looks more modern than the "guts-sticking-out" NX.
IAMD is great in that it canonically disproves the fan complaint that the NX is too advanced for a TOS prequel. The prime universe Connie stomped all over everything in the mirror universe. Considering that the mirror NX was likely more advanced than the prime NX due to the nature of MU starfleet it goes to show just how lightyears ahead TOS tech is compared to ENT tech.
Sir Isaac Newton is the deadliest son-of-a-bitch in space.