We have used Roamless in Canada, Germany, Austria, Switzerland, Lichtenstein, and Spain. It worked seamlessly when moving between countries. Just turn on the esim when you land in Europe and turn off your primary sim. I loaded $25 onto my account at the start of summer. We were in Europe for a total of 3 weeks this summer on two different trips, and I still have over $19 in my account. Your balance stays in your account and there is no limit on number of days the esim is active. We've had no issues with coverage. One other poster commented on another thread that coverage was spotty in England, if I am remembering correctly.