I have used DR Rares, and currently use Newtone MC, both of which are roundcore. I have no set up issues and I can feel a difference with slightly less tension. I much prefer the feel of roundcores. Can't comment on how DR's would sound on an 814 since my only Taylor is a 714 with cedar top.
In any case, the only adjustment might be a slight truss rod tweek, but I doubt that would necessary.