I think with the GaAS we got to remember that Suresh says customers want the whole product monolithic and not discrete. Therefore, the implementation curve would be very expensive and long. In essence, POET would be asking customers to change their entire product lines. Whereas, the OI joins and is compatible with current technology and reduces components cost and raises performance still at a disruptive level to the industry in the now. I think that was the barrier. 

Monolithic