Check out BreatheHeavy's "Sucker" album review
It's an interesting choice using Ora, considering Charli XCX's feature buddies tend to be Ariana Grande or Iggy Azalea (whom she labels a "pop icon") exclusively. But the timing couldn't be more perfect; Rita's releasing her much anticipated lead single in March.
Personally, the song is strong enough to slay radio sans any feature, but we're in the day and age where collaborations are more plentiful than cans of hairspray in Xtina's dressing room. The track has a cool, laid-back background behind Charli's pop punk(ish) tone.
I trust in Charli's musical taste (she's a big Britney fan), so I'll choose to believe she's not ruining an already good thing.
UPDATE: Here's a preview of Rita's part: