When West London soul sista Estelle blew up over the success of “American Boy,” she seemed destined for the big time. But then she slipped off our radar, letting four years pass before dropping her third album, All of Me, a confident-but-underwhelming follow-up that gets a lift from swaggering back-to-back grooves – “The Life,” a celebratory party anthem, and cameo-stuffed “International (Serious)” with Chris Brown – before backing down on her promise: “Ain’t slowing down, I only know speed.” Not for long, though, as she decelerates into mid-tempos that mellow out the get-this-party-started vibe. Of them, “Break My Heart” exposes Rick Ross’ romantic soft side (who knew?), while “Thank You” and “Wonderful Life” are charmingly optimistic, even if none of them achieve the greatness of the artists she’s going for (Lauryn Hill and Amy Winehouse, both of their landmark albums referenced). And those tedious group-therapy dialogues about relationships, acceptance and the ethics of cheating? They’re old-trick and only superfluous to the music, which does just fine covering all the bases of love’s ups and downs, whether Estelle’s loving herself – and rapping about it – on “Speak Ya Mind” or loving up on someone else on the sexy ’80s R&B flashback “Cold Crush.” Two things really shine here: “Back to Love,” a bittersweet song set to a disco shimmer, and a collaboration with Janelle Monae on the sassy girl-group update “Do My Thing.” On All of Me, those things are almost worth the long wait.