When I left Horizon 8 years ago there was no flow through. I haven't heard of any changes since. At that time there was no preference for Horizon pilots except that we didn't have to pay the application fee. The majority of new hire pilots at Alaska came from elsewhere. So I would have said there was no advantage to being at Horizon if you wanted to fly for Alaska. This is pretty old information though, perhaps a current QX/AS person could confirm/deny?