Mostly funny sitcom because of the comedic talents of Eve Arden and Kaye Ballard as the mothers-in-law. The show was produced and often directed by Desi Arnaz so if there's a "Lucy & Ethel" vibe, it's not a coincidence.
Basic plot revolves around neighbors, the Hubbards and the Buells, whose kids marry, making the neighbors in-laws. The mothers are clinging, nosy, and very funny. While Ballard does a lot of her explosive Italian schtick, Arden gets to cut loose from her famous "Our Miss Brooks" persona and display her talent for slapstick. For example: in one episode while the mothers are standing on the garage door handles and peering through the windows (it's been converted into the newlyweds' apartment), the door goes up with Arden and Ballard going up with it.
Being a late '60s show, the women wear wild colors and the houses are decorated with lots of bright orange and yellow. Set against this garish backdrop, the relatively normal husbands are played by Herbert Rudley and Roger C. Carmel (replaced in season 2 by Richard Deacon). The newlyweds are played by Deborah Walley and Jerry Fogel.
Desi Arnaz makes a few guest appearances and both Desi Arnaz, Jr. and Lucie Arnaz show up in a few episodes. Lots of familiar faces show up in guest spots. TV fans will easily spot Paul Lynde, Rob Reiner, Ozzie Nelson, Doris Packer, Beverly Garland, Percy Helton, Jeanette Nolan, Herb Edelman, Joi Lansing, Don Rickles, Alice Ghostley, Mary Jane Croft, Teri Garr, and even Jimmy Durante in various episodes.
But it's really all about Eve Arden and Kaye Ballard.