Complex sentence: Lurchers have also proven to be very good at dog sports such as obedience and agility, where they are becoming increasingly popular due to their speed and willingness to please, again it must be stressed that this will entirely be dependent upon cross.
Split into simpler sentences: Lurchers have also proven to be very good at dog sports such as obedience and agility, where they are becoming increasingly popular due to their speed and willingness to please. Again it must be stressed that this will entirely be dependent upon cross.