Man on a Tightrope was released just one year after Kazan testified before the House Committee on Un-American Activities (HCUA) in 1952. His testimony, which included the giving up of names of former colleagues in the Group Theater to the committee, has in retrospect significantly tainted the reception of his art to the public at large, making it difficult to address the films without at least some acknowledgment of the political actions of their creator.
Most audience members today will point to On the Waterfront (1954) as a prime example of Kazan (and screenwriter Budd Schulberg) grappling with his collaboration with the HCUA. But if you look at this sequence from Man on a Tightrope, I think you'll notice Kazan's social dialectics being applied to not only an examination of the story being told in the film (artists being restricted by the political landscape of communist Czechoslovakia) but also to his own history.
As for the overall quality of the film, Fredric March delivers a solid performance as Karel, the aging clown/circus ringleader who repeatedly claims he's apolitical and is only interested in practicing his trade. Gloria Grahame, playing Karel's wife Zama, is quite good but feels a bit too young and unseasoned both in the role and when balanced against March's performance. Cinematographer Georg Krause, who also shot Stanley Kubrick's Paths of Glory, brings his keen eye for strong framing that supports the sometimes outmoded dramatics of the film.
Tightrope isn't close to the best film exclusive to the Kazan boxset. Personally, I emotionally connected most with America, America (1963), which instantly entered my top 20 list of favorite films. The good news for fans unable or unwilling to spring for the rather pricey boxset: America, America will be getting its own standalone dvd release in February.
Also very good from the set:
Wild River (1960) (hit link for clip) and, especially, A Tree Grows in Brooklyn (1945).