The most obvious difference in the inflight service is that Horizon features regional wines and microbrews, which are always complimentary, whereas Alaska (usually) charges $5 in the main cabin. Early AM Horizon flights from GEG, BOI, SEA and PDX also feature complimentary Starbucks coffee and Wall St. Journals in the boarding areas. Horizon does not carry any hard liquor as far as I know. Another difference is that Horizon has about a 86% on-time rating which is certainly better than Alaska.