Have just bought a second hand Phil and Ted's Vibe for transporting my unruly toddler and the expected newborn and I plan to invest in a new cocoon to go with. Does anyone know if the E3/Sport/Classic/Twin Cocoon will fit the Vibe? They don't look vastly different from the Vibe cocoons and are considerably cheaper! According to the John Lewis website all the dimensions are the same, just wondering if there are any straps/fixings that wouldn't be compatible? Any advice most gratefully received . Thanks 