Earlier I suggested that NET10 was the best ATT MVNO and one of the best MVNO's period in terms of pricing and features provided. I had used the service myself for 6 months and can say, not surprisingly, LTE and H+ coverage were excellent.
One thing not so excellent though is that AT&T seems to give data preference to it's direct prepaid and postpaid subscribers as opposed to those who subscribe to their network via an MVNO. I noticed this personally, and have read of others reporting this as well. This "data dropping" is not always obvious as your phone will signify in it's status bar that it is connected. In fact it took me a while to realize it myself. The problem became apparent when day after day all of my push notifications/messages would be delayed. Sometimes as long as 45 minutes, regardless of what server was pushing something to my phone.
Sometimes you'd have to start the app, such as Hangouts, or Gmail in order for your phone to connect to data and have a message pushed. Obviously, this isn't particularly good if you are awaiting urgent information or conducting business. I would also notice the problem when I would try and connect to the web via any one of my browsers. The first time I would try and load a webpage I would often get offline errors. Fortunately though, in situations where I needed a sustained connection like when streaming audio (which you technically are not supposed to do on NET10), I never experienced data drops or audio buffering problems. Sometimes when driving though, if one of my gps apps required a reroute, I would experience a little longer of a delay than when I was on ATT in updating the map and recalculating the route. This wasn't particularly good when I required a quick reroute to be able to take a quick turn. Fortunately, I can also report that on the voice side of things I never experienced dropped calls, so those of you that require good voice coverage need not worry on NET10.