The Girlfriend Experience, Edinburgh Film Festival, Edinburgh

Two decades since winning the Palme d'Or for Sex, Lies and Videotape, Steven Soderbergh returns with another film dissecting the sexual mores of the American middle classes. If you count his recent Che double bill as two separate films, The Girlfriend Experience is his 20th movie in as many years – a remarkable achievement by anyone's standards. Such a prolific output has not always brought stellar results – whether it's the two Ocean's Eleven sequels or the Second World War noir The Good German. Not so The Girlfriend Experience, one of the most engaging and astute works of Soderbergh's career.

Like his earlier film, 2005's Bubble, this is an HD-shot, lo-fi drama made for $1m – with the idea (in the US, at least) to unveil it simultaneously on DVD, cable and in cinemas. But while Bubble never even made it to the UK – its cast of unknowns and story of a murderous small-town factory worker evidently troubling distributors – The Girlfriend Experience is accessible as well as provocative. Written by David Levien and Brian Koppelman, who penned Ocean's Thirteen for Soderbergh, it's the story of call-girl Chelsea, and one of the most cliché-free views of selling sex seen in years.

Played by the real-life porn star Sasha Grey, Chelsea is no battered, drug-dependent hooker. She's smart, literate and articulate, even keeping a diary to document her time with various Manhattan high-rollers. Most can't stop talking about the economic crash. She lists the clothes she wears for them with the same obsession as Bret Easton Ellis' American Psycho Patrick Bateman. When she's not seeing clients, delivering "the girlfriend experience", she's working on self-promotion – meeting web designers to try and get her site ranked higher in Google's listings.

One sequence sees her meet a journalist who wants to get to know her inner self – which she admits is closed off to nearly all men. We meet the one she's let into her life, a personal trainer named Chris (Chris Santos). They live together, trying to make a relationship work in impossible circumstances. Chris, in one recurring sequence, is on a private jet with a group of hedge-fund managers heading out for a hedonistic Vegas weekend. They talk sex, business and politics – and all three seem inextricably linked. Selling your body, it seems, is no different to trading on the New York Stock Exchange.

Despite some nudity, crucially there's no graphic sex in the film – and Soderbergh evidently didn't hire Grey to exploit her. Rather, he taps into other qualities; not least that, like Chelsea, Grey must inevitably remain detached to work in the sex industry. There's even time for an appearance from the former US movie critic Glenn Kenny, who plays (superbly) a sleazy web-reviewer who ultimately hacks at Chelsea's reputation on-line. If that may seem indulgent, it's not. Soderbergh's judgement never falters here for a second.

On general release on 20 November