Remains to be seen how this is going to work out in practice. For example now I pay flat rate for my unlimited 4G subscription. When I travel, my own operator will need to pay per gigabyte price for the network provider. This may put some pressure on my own operator to raise the price they are charging from me.
Here's [1] some information on how EU views the wholesale pricing.
"With regard to caps for data, the general approach introduces a declining glidepath, with the maximum charge starting from €0.01/MB on in mid-2017 and dropping gradually to €0.005/MB in mid-2021."
So if I understand right, when I use 1GB of data on my roaming trip next summer, my operator might end up paying 10€ for the local operator, but is not allowed to transfer the cost to me.
I don't really see how this can work out, unless there will be quite heavy data caps for the free roaming.
out of curiosity, which country is this and how common it is among others? in Czech republic I am seen as a weirdo when I use around 10gb/month - most people are comfortable around or under 1 gb.
in CZ you can't get unlimited LTE plan AFAIK. The most expensive plans are around 30gb. Current speed in metro area is approx 70 mbit with a regular LTE phone without special antenna.