Their customizable plans make it simple to choose the perfect mix of talk, text, and data. Far cheaper than any other major carrier. I have not had any connectivity issues or call drops/failures. I was able to use my unlocked phone from a Verizon line and port in my existing number. Instead of paying $65+ per month, I've increased my service limits and reduced my monthly cost by over 75%.
The only drawback: Tello only allows one line per account, so I have to manage three separate accounts for our three different phone lines. But I use my referral code (P3D24JJD) and get $10 for each new line I set up, which is like getting a rebate back for the Sprint SIM card I need to purchase to transfer over to Tello. Additionally, check online for discount codes (15-30% off first order) to save a few more dollars when signing up.