Far superior to other carriers, like AT&T or T-Mobile
A carrier I actually like—AMAZING! I pay $9.89/mo, including taxes. My only complaint was having to pay $10 for a SIM, not realizing any Apple store will give me any iPhone SIM I need, for free. Whoops!
AT&T and T-Mobile prepaid/pay-as-you-go plans all have serious shortcomings. Other carriers weren't even worth trying based upon their own descriptions of service.
Tello even let me turn off voicemail—nobody else would. With voicemail activated, there's no way to avoid being charged for telemarketing calls, wrong numbers, and other annoying calls. Without voicemail, I get the satisfaction of letting the phone just ring. If anyone I know needs to leave me a message, they can send me a text or an email. Voicemail is so 20th Century!
As an added bonus, I have a stronger signal in my home with Tello than with either AT&T or T-Mobile. Tello uses excess capacity on Sprint's CDMA network, and where I live that's a good thing!