Horizon is the former High Sierra (and before that Sahara Tahoe). NOT the small Harvey's Inn. Horizon is next door to Harvey's (on the lake side of the highway) & across the street from Caesars Tahoe. It's one of the 4 major hotel casinos all located in walking distance of each other. (plus a 5th small casino -- Bill's -- next door to & owned by Harrah's).
I stayed at Horizon about 3 years ago and liked it just fine. True, Harrah's & Harveys are a bit nicer rooms, but for the money, I would choose Horizon again, as I don't spend that much time in the room anyway.