Perhaps inspired by Ed Sullivan's successful years of presenting top international acts as well as American stars, young and old, ABC mounted their own big budget variety show, naming it for the famous theatre that housed it, The Hollywood Palace. They were able to get their share of big names, and a decent mix of the magicians, animal acts, clowns and acrobats that populated foriegn circuses and stage shows that Sullivan might present, (or had presented- by chance I saw a May 1961 Ed Sullivan show and an October 1965 Hollywood Palace in the same week, and both had the same Japanese trick bicycle girl, in the same costume, doing the same bit).
It's said that the HP had a problem finding a personality, that Sullivan himself, though stiff, ill-at-ease and given to stumbling his lines and mangling introductions, gave his show a certain charm and connection with the audience. The HP's formula was a revolving host/hostess that would be a star himself. But there was the problem- it was too, too slick. If Ed was short on warmth, he had real humanity. The super polished personna of say, Gene Barry,Tony Martin or Steve Lawrence, oozing pretend laughs and sincerity lacked it.
Another thing that contrasts the two shows, and may be the most damaging, is the production itself. Ed's show stopped being completely live with the advent of videotape in the late 50's, like most programmes. He did a mixture of video and live material for a while into the sixties, and kept that certain spark of life alive. But the HP has nothing live ever. Every single foot is carefully rehearsed, then edited from multiple takes from different angles. All the life is smothered out of it.It's carefully controlled, prefabricated and sometimes rather noticably helped along by canned laughter.