Currently using Mocolo for iPhone 6 and Note 4. Being trying different brands of Glass Protectors (mainly branded ones from retail shops) for both devices, I must say that I found Mocolo one of the best! Despite its low price, its quality is top notch.
For the "air bubble" / "helo effect", I think it is due the curve in the respective device. I understand that different device have different curve due to batch and output from different factories.
i.e. same glass SP might be ok for some but with bubbles for others. This also applies to non full frame glass SP.