Slow Club, Shepherd's Bush Empire, London

Slow Club's first record, Yeah So, could have been maddeningly twee: it was the sort of sprightly, lo-fi, folk-pop whimsy that ends up soundtracking cutesy indie movies or mobile phone adverts – and it came from a boy-girl two-piece. Yet there was also a roughly hewn, even strained quality to the vocals, while being a band of only two produced both intimacy and intensity.

But that was 2009; in 2011, they've released a new album called Paradise, which ratchets things up a notch. They have a much bigger sound, with stronger vocals from Rebecca Taylor that now easily match those of guitarist Charles Watson. Live, their new found oomph is recreated with the addition of a backing band and even a string section (albeit underused). From the opener, "Where I'm Waking", we are in fairly rockin' territory; they may have a full-time drummer, but Taylor has her own set, too, which she proceeds to wallop with gusto (it seems no female vocalist worth their salt can get on stage without a tom-tom to pound in an attractive manner these days...)

The beefed-up sound benefits some of their back catalogue, too: the post-adolescent angst of "Our Most Brilliant Friends" (the lyrics continue "are doubting themselves") sounds less reedy and more substantial here, while "Giving up on Love" is furiously fast and ridiculously enjoyable. They also venture successfully into new territory with the bluesy "Never Look Back", which showcases the chocolatey richness of Taylor's voice.

Their slower moments, however, veer towards treacly – those voices in unison can be lovely, or can wallow in a harshly melancholic mire, as on the yawningly paced "Horses Jumping" or "Hackney Marsh". But most of the evening is served up with a generous dose of charm, aided by their very warm stage presence: Taylor, in a mini dress apparently made from a Sheffield Wednesday strip, announces that this is "the biggest gig we've ever done... no big deal!" before adding sweetly, "so proper thanks."

Watson – skinny, black-clad, with a good line in hair flicking – is endearing too; when they return to the stage a second time, obviously chuffed, he announces that "I feel like a total dick doing two encores." Generally, I'd agree with that assessment, but their final number, "Christmas TV", performed on acoustic guitars and without microphones, is so adorable I'd forgive them as many encores as they liked.