Xfinity really sucks if you're used to FiOS. I don't see it mentioned here, but it was an issue when I had Xfinity; they have data caps unless you use their modem or subscribe to unlimited data. It was an extra $30/month for me because I didn't want to rent their modem that's significantly worse than the one I already owned.

As others have mentioned, the upload speeds are pretty bad and the internet will probably be slow during peak hours. It was an issue for teams calls.