By service, do you mean your data & cell service on the phone?
If so, then that's just T-Mobile. I don't think the phone itself has much to do with the coverage you receive.
I don't have the One, but an overall jist of what I've heard is that the build quality is solid, Sense 5 is a huge upgrade from Sense 4, buttery smooth, and that boomsound is amazing quality over other phone speakers.
People do say they wish it had a removable battery and microSD but if those don't concern you, then it shouldn't matter.
I heard mixed reviews about the camera so I can't say anything about that.
Also, to see how T-Mobile's coverage is in your area, go to
Coverage Maps | Sensorly