Last Night's Viewing: Beyoncé: Life Is But a Dream - an Imagine Special, BBC1 James May's Man Lab, BBC2

Five years ago, when Alan Yentob got a rare chance to appear awkward in the company of Jay-Z, he was accused by one reviewer of delivering "interminable gushing guff" about the gazillionaire rapper.

Perhaps there was more of it in the presenter's brief introduction (it wasn't available for preview) to last night's documentary about Jay's bigger half, Beyoncé: Life Is But a Dream – an Imagine Special, but any gushing thereafter must be blamed on the film's director, producer, presenter and star: Beyoncé.

This was autohagiography at its glossiest, a big-budget film that scored record viewing figures for HBO when it aired in the US last month on the same night as a fawning Oprah interview with the same singer. But Americans really go in for hero worship, right? Who even wants the awkward back-of-the-SUV questioning of a Yentob, or the studio tear-drawing of a Piers Morgan? Beyoncé's pretty much a saint already, let her do her thing.

Well, if, like me, you don't adore her as millions do, but you admire her a bit and are curious, the view of this vanity mirror was always going to be obscured by inflated ego. Fine for the extras on a tour DVD, not so much for a broader audience with questions of their own. Why did your relationship with your father become so broken? What sort of life did your parents have in that lovely house? What happened to those sisters you were playing with as a child in that cute home video? There was nobody to ask her.

But as an exercise in self-promotion, Life Is But a Dream was arguably worthwhile as a different sort of production. What sort of film does a mega-celeb make about herself? Beyoncé's attempt combined home video, webcam diaries, concert and rehearsal footage and a massively staged interview in which a giant sofa played a bigger role than her interviewer (we never even saw his face).

Viewed this way, the result was a compelling, 90-minute tour of a life and an ego. The gooier parts, in which she expressed undying love for God and Jay-Z, were leavened by the sheer energy of the concert scenes. And her dedication to getting stuff right was impressive. At one point, she rehearsed a dance sequence in the corridor of her hotel, pausing briefly as an unfazed maid shuffled past pushing a trolley.

It was not without emotional insight, either. She discussed her miscarriage, first baby, and marriage. But the film was ultimately an exercise in the control of a brand and a (selectively) private life. She bemoaned press intrusion while holding up her baby to the camera and sharing footage shot on yachts and in private jets. And she rounded on those who had spread cruel rumours claiming she had had a baby by a surrogate mother to save her the inconvenience of childbirth. "To think I would be that vain," she said. I guess there are degrees of vanity.

James May. Thoughts? It sort of depends if you used to like Top Gear but now can't bear it, or if you still lap up that tired brand of middle-aged-man banter. I fall on the weary side so had issues with James May's Man Lab, his "quest to rid modern man of his own burgeoning incompetence" by way of a series of massively hackneyed tasks. Seriously, how often have you seen a TV presenter having a go at commentating on a horse race? It's not that I dislike May, easily the least offensive Top Gear presenter, but I needed to be given more of a reason to care about his ability to distinguish horses going quickly, and I struggled. It didn't help that he'd already lost me by then by using of the word "amazeballs".

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