My car came with the 255-60/15 and 275-60/15 Goodyears GT II's. I could spin them in 3rd gear if I flat footed it.
After a crap load of research I went with the Goodyear BillBoards and love them.
Been meaning to do a report on them, so I guess this is as good a place and time as any.
Rolling Resistance - Since I always push the car out of the garage, I have a pretty good idea on this. They have considerably more rolling resistance that the GT II's.
Flat Spotting - Yep, they flat spot, but within two miles they are fine. To me this is a non-issue.
Rocks - They are soft, and rocks do stick to them and get thrown around. I used a gallon of Herculiner on the inner fenderwells and I don't have to worry about rocks starring the paint.
Following Ruts - Sometimes yes, sometimes no. Depends on the road. My wife has a Jeep SRT/8 with the Goodyear run flats. On some roads it follows ruts worse than the Cobra. To me they are not that bad.
Balancing and Roundness - They balanced out the first try, and no out of round conditions.
Traction - Great.
My only regret was waiting as long as I did to buy them.
Hope you will be as happy with your decision, whatever it may be, as I am.