I've got both at the moment, not used either for deer. The GSD is more inclined to track though.
He is not bothered by any weather either, quite happily lying outside his kennel in snow (on the rare occasion we have any). Might be a consideration if you spend much time in seats.
Do you have any experience of Malis ? They wouldn't be my first choice just as a stalking dog, but as said if you've got any 'undesirables' about either breed could be useful.