what ever the % dont really mater, its the weight that counts. To much weight you loose agilty, my last2 bullxs were 70- 77lb. They were fast+agile, and unless you get the fox close, you will need all that agilty catch the fecker. A fox is fast and can turn like hares at times .
that just about sums the fox up. i often wonder which is the better turner the hare or the fox.
i,d say the fox . and the dog has to learn his game quick, as we all know the fox is the best at pulling out all the tricks and making his get away