We need new tires for our spread and would like to hear from this group...

We currently run the XZE* and they seem to wear very well but their rolling resistance is pretty high. The competition in this group w/mpg improvement appears to be the RY023 (.7%), the HSR1 (1.5%), the ST230 (2.2%) and the R195F (5.9%).
The ST230 looks best from a cost and mpg view. The R195F looks best from a mpg but is the highest cost of the group and I don't know how it would wear in the spread position. Is anyone using the R195F in a spread configuration?

 

I think I am going to put the XZE* on the forward spread and the ST230 on the rear spread. Are there any thoughts on this?