The Bally's Tower rooms are larger and nicer (and offer a nicer view.) If they did any makeover on the Tower rooms, like adding LCD's, that would make these even better.
Generally Saturday night stays in AC(even for Diamond level players) were not listed as "free" or "comp"--but now with the economies downturn, they seem to be available--but at least for Bally's, they put you in the Dennis Tower (or sometimes in the Claridge) [In one of the posts on FT, the poster described a Claridge room as something one sees on TV, where they take you to be interrogated.]