A while back my service dropped by 10mbit down. This stayed the same for about 2 weeks. I had to regularly power cycle the Huawei modem and it went back to what it was. For months I have kept the same rock solid speeds at 33mbit down. Then a few days ago my service went up by 4mbit down! I have been on Infinity for two years and I am now on the fastest speeds I've ever had. Not quite the 10 day stabilisation period but there you go.
Maybe someone upped the transmission power at the cab - an engineer may have installed someone elses service and I am enjoying this due to a decision to change something in the cab that we mere mortals can only wonder what