my honest opinion is that you'll never know if you don't try them and feeding goes a long way towards there performance m8's of mine have a hen which has won bourges 555miles 4 times in succession and is vandenabeele on one and through birds that have never won past clermont 405 miles they had what they call there old bourges hen won it 3 times which is a rene neawlaert and what a lot call middle distance lines this hen has bred umpteen winners but none have won further than clermont