Bernard Slade is two of a kind. His writing, as currently reflected in "Tribute," the all-too-faithful movie version of his successful Broadway tear-jerker, seems to combine the worst vices of Neil Simon and Paddy Chayefsky -- relentless quipping and gaseous editorializing -- with little of their sometimes saving wit and authority.

Slade's snappy repartee often sounds gummed up the instant it leaves his characters' mouths. There's even a line in "Tribute," opening today at area theaters, in which Slade himself seems to notice the problem. "I've lost all the prelims," says protagonist Scottie Templeton, a wisecracking wastrel of a Broadway press agent who learns that he's dying of cancer. "Maybe I can win the main event. . . Gee, that line sounded better in my head than it came out."

So does many an infirm nifty better left in the writer's trash basket. It's ironically fitting that Slade should be unable to resist salvaging this glittering zircon: Scottie's character flaws are treated with the same jovial indulgence.

"Tribute" is designed to glorify an admitted but incorrigibly self-approving show-biz sellout. The trick is turned by confronting him with a priggish antagonist -- his estranged son, an awkward and inexperienced college snob -- whose intolerance can be manipulated to outweigh his father's formidable yet forgivable sleaziness.

The reconciliation demands a heap of contrivance. After a separation of 13 years, the son, Jud (played by Robby Benson), is persuaded to extend a brief stopover in New York at Scottie's apartment. Several misunderstandings later, blood proves thicker than temperature, and Jud ends up an awful show-biz "arranger" himself, staging the concluding testimonial dinner at which Scottie, just out of the hospital (an ordeal documented in heart-rending, fulsome detail by Jud's photojournalistic camera), signs off like a sanctimonious Archie Rice, treating his deeply moved peers to the irresistible show-folks baloney of mawkish shows of affection in public and Platitudes To Live By.

"If there's one thing I wish for you, son," Scottie wearily avows, "it's passion. For anyone, anything, but just go the distance. I never had the courage to put it all on the line. I missed so much." As father and son fall into a damp embrace, the audience beams and applauds, and Barry Manilow takes charge of a soundtrack benediction by singing the soom-to-be-Oscar-nominated theme, "We Still Have Time."

I fear that I was predisposed to dislike "Tribute" under the best of circumstances -- too dumbfounded by overacting and miscasting to entertain the vaguest thought of suspending sympathetic disbelief. The idea of Jack Lemmon and Lee Remick, cast as Scottie's oddly doting ex, being the dad and mon of Robby Benson seemed astonishing enough for starters.

You can tell how Scottie must have dominated the stage show, but shouldn't it have been obvious to both Lemmon and director Bob Clark, a fairly skillful filmmaker, though new to theatrical source material, that an actor's control over movie space and tempo is severely limited? The performance doesn't appear to be adapted to the screen at all. On the contrary, it spurts and crumbles all over you.

Of course, the sentimental presumption and artificiality of the text would tend to invalidate any performances at close quarters. John Marley isn't really bad as Scottie's partner, but you still wish he'd get lost when he scolds Jud: "Your father has the enormous gift of taking a hamburger and making everybody around feel they're at a banquet. Now if you don't think that's a great thing, well, there's something wrong with your sense of values."

In a similar respect, the young actresses Kim Cattrall and Gale Garnett, respectively cast as Jud's girl and Scottie's favorite hooker, would probably seem better if their talents and looks weren't appropriated for singing the praises of Saint Scottie. Cattrall, who has a lovely face and voice, is almost undone by repeated bell-like laughter at the antics of the lovable old scamp.

Incidentally, couldn't we have a moratorium on all-choked-up father-son reunions? The request may sound like sour grapes coming from someone with three daughters, but the atmosphere has been getting a little thick with drippy masculine bonding ever since "Kramer vs. Kramer" became a hit. One on the funnier consequences of neo-feminist self-approbation is the accompanying inferiority complex suffered by insecure male writers and directors, now inclined to overcompensate by pretending that men will appear more virtuous if they adapt female behavior patterns. "Kramer" was one thing, but after "Ordinary People," "The Jazz Singer" and now "Tribute," this masculine bathos has got to stop.