Here is what I did.
I used a ramp. I pulled my left front tire up on the ramp and took measurements at all four fenders. This was done stock. Then with the sway bar disconnected and with polyurethane bushings installed. The difference from side to side was subtracted, then the difference was added to the rear. The percentages were calculated from there. The percentages did closely mirror the front alone. I wanted to add the rear measurements to allow for some frame twist. It didn't amount to much since the front alone was virtually the same percentages.
If we call disconnected our baseline the stock bushings decreased body roll by 6%. Poly bushings decreased body roll by 23%.
What does this mean? Well, having the sway bar disconnected and running the stock bushings , the body is tipped 6% less than with the bar attached. Once I added the poly bushings this percentage really increases and the body will tip with the frontend 23% more than it would with the bar disconnected. The bar being disconnected then makes a big difference.