ARR letro vs Liquidex

Does anyone have any experience using both ARR's letro and liquidex (anastrozole)? Which did you prefer and why? I have had great success with ARR letro in the past, but am thinking about trying the liquidex in my experiments. My reasons for this are my rats want to avoid an estrogen rebound and will aslo be running nolva as well to help improve their lipid profile. Nolva hurts the strength of letro where as I have not found any info on nolva reducing the strength of anastrozole. Any comments?