My US wireless carrier (Verizon) sells a service that claims to allow me to use my phone as usual while in Europe, for a flat $10/day. There's no mention of changing SIM cards, per-minute charges, or anything like that. That sounds too good to be true. Does anyone have experience with this service (TravelPass)? Is it as advertised?

EDIT: it's a GSM-compatible phone. I checked.