Irving > IT
not by much though -- certainly not enough to justify swapping them and whatever other assets Cleveland would ask for particularly when IT has helped recruit Horford and Hayward and is now basically the face of the franchise. supposedly players in the league (some at least have stated as much) see IT as someone desirable to play with -- not so sure that's the case with Kyrie.
While both are poor defenders, IT's issues are height-related, not effort-related. Kyrie just doesn't bother. if Kyrie bothered to play D, I'm sure he could at least be average if not better than that but is he willing to make that effort after this many years in the league?
Offensively, I think it's a wash. IT can score in so many ways it's unreal. his ability to finish with a basket and draw contact is a real asset (it'd be even more of an asset if we had a big man that was an actual threat in the post who could also get the other team's bigs in foul trouble). Kyrie can almost get to the rim at will and has the height to finish without much issue. I think Kyrie is a slightly better distributor but that's my own personal view.
In the end, it doesn't seem like enough of an improvement to swap the 2 of them.