Project Fi worked great in Germany & Austria. Service was very bad in Italy. Cust Service kept on giving me different stories
Sort of a review; (+ of Sprint's stupidness)
I signed up for Fi using Dan's link - I poped the sim in my old Nexus 5X (didn't even try to use it) for a week. The day of my trip I wanted to move Fi to my P2 & Sprint to N5X. Knowing Sprint has issues reusing Sim Cards I had ordered a week before a new Sim Card from Sprint. I pop my sprint Sim Card in my N5X but I can't get it activated. After some calls with Sprint (They said my Phone was activated on a different account) - I called Fi (3 calls did the trick) they removed my N5X from their system (One claimed I have to cancel service & open a new account.....) & had Sprint remove the P2 from their network. Once I removed the Sprint Sim Card from the P2 it Automatically switched to the e-sim which promoted Fi to activate. Meanwhile on my N5X I wasn't able to get Sprint 4G - so after many calls they decided I need a new sim card (but I had a brand new?)
Germany & Austria - 4G LTE all the time.
Italy - only H - and very spotty and dropped calls. Called Fi Support, and the first agent came back plain we are updating our intl servers - it will work in 3 days.... (He was reading from a memo - whatever). The next call the agent tried to assist with troubleshooting - I asked that if I get disconnected she should call back & of course never did. Called again and the agent asked for some troubleshooting again and said she has to check with level 2 and she will call ack - and of course i'm still waiting. I got an email with a whole lists of steps, I tried to answer whatever possible but they didn't want to assist if I don't answer all.
And then I just came home....... and the fun started to swap back the P2 with N5X. It took 3 calls again to Fi to Unlock the IMEI - even as I said it very clear on the first call (didn't have to guess the issues that will arise) and the agent said very clear that it was done on the first call. What I had with Sprint is too long of a story. A later complaint to Fi got me $20 service credit.
I borrowed my phone now to a sibling, - and she she meanwhile in Poland & Israel she had 4G LTE.