Just to confirm, SMS notification is useless. I was downloading Debian CD and had to watch counters, as CD size was 30 Megs bigger. Download speed from local server was about 4Mbps - not a lightning LTE speed. Just 10 seconds before cutting the connection SMS arrived. Is says I had 406MB data left, but I stopped when it was 20MB left. Not sure about exact figure, as statistics sometimes get updated 24hours later.