These shows have their moments, but all in all, it's true; they're mostly stale and uninspired. Guest stars and "exotic" locales try to give the proceedings a shot in the arm, but most of the time the guest stars look pained and uncomfortable (you're almost embarrassed for Maurice Chevalier getting caught up in Ricky and Lucy's increasingly realistic and unpleasant fighting). Episode by episode:
Lucy Takes a Cruise to Havana: A novelty in that it "flashes back" to Lucy and Ricky's first meeting, it's also not terribly funny and often quite dull. Lucy and Ann Sothern have some good chemistry but the material isn't there. It also contradicts some of the "canon" of the "I Love Lucy" series, but that's not really all that new. Worth watching once for curiosity value; just don't expect a lot of laughs.
The Celebrity Next Door: Easily the best of the lot, and coincidentally, the last in which Lucy would wear her trademark hairdo. Thus, it still FEELS like a Lucy episode. Tallulah Bankhead gives as good as she gets and practically steals the episode. The final "play" is amusing as well. And remember, folks, "When Miss Bankhead is bored, Miss Bankhead will let you know."
Lucy Hunts Uranium: A bit predictable, but the location shooting and the "It's a Mad, Mad, Mad, Mad World" hijinks at the end are good for some smiles. Fred MacMurray is fairly likable in his star turn, though Lucy and Ricky (the characters) are starting to get a little too cavalier with how they treat celebrities! Would you leave Fred MacMurray in the desert to die?
Lucy Wins a Race Horse: Not a terrible episode, this still predicts the more tired humor of "The Lucy Show". Lucy and Ethel pushing a horse upstairs is worth a few laughs. Ricky, however, is just starting to look hollow-eyed, gray and tired.
Lucy Goes to Sun Valley: The tension between Lucy and Desi is becoming palpable, but not quite pronounced. There's not really much interesting in this episode; its major set piece seems to be each character interrupting Fernando Lamas as he's taking a shower.
Lucy Goes to Mexico: A truly irritating episode; Lucy and Ricky's aforementioned bickering now seems to have a nasty edge to it. The hijinks just seem strained here whereas they were effortless in the European ILL episodes. However, Lucy's turn as a toreador at the end is kind of amusing, albeit very "Lucy Show" in the writing.
Lucy Makes Room for Danny: I never really liked Danny Thomas much; the kids almost save this episode by generally being more likable than the main characters. Gale Gordon does have a funny role at the end as the judge who calls Fred "a miserable tightwad." All in all, though, the original ILL "Courtroom" show is funnier.
Lucy Goes to Alaska: Red Skelton DOES come off well in this episode, charming and guileless. I'm not that fond of his routine with Lucy in the middle, as it goes on too long. But the sleeping scene is okay, and the final scene with Red flying the airplane has a little suspense to it.
Lucy Wants a Career: Simply put, this is an hour long "Lucy Show" with special guest star Desi Arnaz. Lucy is a dim bulb through most of it, doing stale slapstick and irritating the hell out of Paul Douglas (whoever he is, he's not exactly a charmer). The original "I Love Lucy" charm is just about gone.
Lucy's Summer Vacation: A dull episode whose idea of a comedic set piece is Lucy and Ida Lupino plugging up holes in a boat with chewing gum. Almost instantly forgettable.
Milton Berle Hides Out at the Ricardos: My God, Desi looks horrible in this episode. Hollow-eyed, listless, gray and tense, until the moment when Ricky becomes inexplicably psychotic and punches out Milton Berle, thinking Uncle Miltie is Lucy's paramour. Then there's the final scenes on the crane, with Lucy's stunt double painfully obvious, as she looks nothing like Lucy. Perhaps the worst of all the Lucy-Desi Comedy Hours...
The Ricardos Go To Japan: ...to be followed by one of the best. Sure, it may be as authentic to Japan as an American-made sushi roll, but Bob Cummings is fairly funny, and Lucy and Viv recapture their original chemistry all over again. A fun episode, worth rewatching.
Lucy Meets the Moustache: However, in this last episode, Lucy and Desi are back to their usual distance and it shows. Ernie Kovacs is not a natural to this kind of comedy, though Edie Adams does all right. This isn't grade A but it's not a total waste of time, either. Even though it's all been done, at least you can see it being done with the original cast one last time, and that's not so bad.
Overall: Worth seeing once. Not going to stand alongside the original half hour. "The Celebrity Next Door" is a keeper, with "The Ricardos Go To Japan" being a runner-up. Everything else... see it for the historic value, then let it alone.