Wow this could not have come at a better time. I was sooo close to moving ISP until just read this tonight.
I'm currently on 46gb of a 50gb monthly quota so the rest of march will have to be low usage or most likely i'll pay an extra £10 for 10gb as lots of things I want to stream this week.
But yes 100gb is a nice increase and will allow me ample bandwidth.
So looks like Zen will be my ISP for the 5th year.