I am sorry to say I have been in the exact same position you are in. BTW - A ping of under 100ms to the mast is pretty good going for
IBB! I had the 2MB service and i was always getting 50-60% packet loss and latency was a joke.
They do not have the infrastructure for the amount of users...dont kid yourself by thinking it will improve - it wont!
I am now on BT, and my ping RTT is 21ms !!
If i can offer you any advice at all, its to go with a different provider.