glennie2, XFINITY Mobile combines the nation’s largest 4G LTE network with our 15 million XFINITY WiFI hotspots.
If you'd like to check out your coverage, you can use this link to get more info:
Here is the map for our hotspot coverage:
Short answer: Speed - No, Coverage - Yes.
Speed: As mentioned above, LTE latency is the big issue, but hopefully Comcast will make some changes and improve this. I think latency is a much more important factor than most people realize. It affects almost everything you do with your data connection. You can run a network speed test with Xfinity Mobile and see some really good LTE throughput numbers, comparable to Verizon, which can make you think you have a fast connection. However, in reality, it's hard to see those numbers in everyday use. For example, look at just loading a simple web page. The time to transfer the data is generally insignificant regardless of your LTE throughput number. However, loading that data typically takes a number of round trip messages to the server. If it takes 10 round trips, with a 30ms Verizon latency, that means the web page can load in about 1/3 of a second. With an Xfinity latency of 180ms (which is roughly my current average in Seattle), that means the same web page takes almost 2 seconds to load. Your numbers and experience will vary, but in general be prepared for things to feel a bit slower with Xfinity.
Coverage: It's really good. Xfinity advertises the same coverage map as Verizon. If there is a Verizon tower nearby, you should be able to connect to it. The only possible exception might be roaming. We suspect that Xfinity doesn't have the same roaming agreements as Verizon does with third parties. If you commonly roam off Verizon's network this might impact you, but for most people this is a non-issue.
Other: Xfinity Customer Service has some real issues right now. Hopefully they'll get those worked out soon. But Xfinity is an MVNO who licenses Verizon's network, so they are unlikely to ever have the same level of expertise as Verizon. Also be aware of some feature differences such as no wifi calling on Xfinity (but it's supposedly coming soon). Xfinity also doesn't offer any customizable options such as data caps for individual family members.