With the slick looking, more advanced NX class Warp 5 cruiser, can we really take the Warp 7 Daedlus class ship serious now? Obviously, created WAY before the NX and an early version/forebare of the Constitution class. It is so out dated looking, and fragile, that to shoehorn it in between the sleek NX and the classic Connie, is a bit hard to swallow. Yet it is cannon and is an established class.
http://memory-alpha.org/wiki/Daedalus_class
That's not hard to answer. How can you take the TOS Enterprise seriously after the NX? Typewritten display screens? Computers which reply with unnecessary noise in a robotic voice? Still, evidence from ENT and TNG+ has demonstrated clear unwillingness to tinker with the established TOS Enterprise (aside from tiny, almost imperceptible differences, some of which were introduced because of production limitations). Therefore, I see no problem with keeping the Daedalus (nearly) exactly the same.