For those planning to travel to US, my recommendation is to get local SIM-card. The EU-limit of 62,- € will be reached pretty much immediately. The data roaming prices are insane. 1,- € / 50 KiB or similar. The SIMs sold at the airport cost three times more than the going price at the street is. I just went to a local T-Mobile store and got a pay-as-you-go card. Fee for the SIM was $15 and 1 GiB of LTE transfer was $10, making the total $25. You can charge more gigabytes to the account if you run out.