Zact works on the Sprint network, so the service can be spotty at times, but you're not paying for any more than you use, and services can be increased or decreased at will and at any time. Call Quality Call quality is passable, but I believe that a big part of it depends on the phone you're using. Coverage Coverage isn't exceptional as it's on the Sprint network. Also, unless a building has a repeater installed, you may not have service in some of them. Plan Options You can customize your plan at any time for whatever your needs are at that time right from your phone. Features When they have phones available (availability is limited at times) they are all smart phones, thus the features are virtually unlimited. Customer Service It has been my experience that they are quite prompt at answering any questions one might have.