I was told by someone who claimed to a guru that 4G carries a significantly higher overhead that 3G. All our equipment is elderly/cheap 3G. So far this year we have burned 4.3GB in 3 weeks. We listen to BBC radio most evenings, and have downloaded several chart and map updates.
In my experience, Wind is cr@p. Only works near centres of population. Low bandwidth. Anywhere near Albania it connects to some Albanian ISP and runs out of something, so you have to find a Wind shop and give them 5 euros to reset.