The big problems with MVNOs is they don't own or operate their own networks. If you need help, calling the carrier directly is not an option. They will give you the phone number to the reseller and that is it. If the resellers support is no good, hanging up and calling back will likely give you the same person. Spectrum is the latest MVNO that jumped into the Cellular business. Since all the wireless carriers like to start their individual plans at the $70 mark, these guys came out with a $45 per line deal. For single line users, that's not a bad deal but if you are a large data user like me, it sucks. Not because of the wireless network, that's Verizon's. It's the fact that Spectrum will throttle your speeds down at 20GB. That's less than all the major carriers and not even half of the 50GB of 4G LTE T-Mobile gives their customers. Don't expect free global data and texting and many other features offered for FREE that the carriers offer their direct customers. Spectrum also utilizes wifi hotspots which may or may not be as secure as using encrypted cellular services.
Since I am often asked what plan I'm on personally, here it is...
Assuming your also a geezer like me, T-Mobile's 55+ Senior plan is their best kept secret, and by far, the best deal out there. It offers one Unlimited line for $50 which is fair but two Unlimited lines for $60 which is stellar.
Initially, they only allowed for two lines but I believe they will now allow a third line now for $35.
Anyone in the military can usually get a military discount, usually about 15% off, if you don't ask, you won't get.