I'm in Southern NC probably not far from you. Same clay.
BX24 with loader B'hoe etc.
(Obviously, I take off the FEL and BH to mow) Turf tires do fine for traction on the grass. FEL work is ok since the 4wd and dif lock make a huge difference over 2wd. I wouldn't put the R-4s on my lawn. The R-4s have a greater load per psi than the turf tires and the red brick soil I have doesn't need to be packed any tighter. Even the turf tires can do some damage in the turns just from the weight of the tractor and from scuffing on the sidehill passes...
Summary: I'm glad I got the turfs. I haven't had a situation where I absolutely had to have the more aggressive tires. The turf ties do well enough that if even I had a mounterd set of R-4s, I certainly would not be very likely to change back and forth to get my work done.