I was hesitant to try it, but once I ported my number over, it's the best service I've ever used.
It's $5/month, and your phone calls and texts are forwarded to an XMPP account. Voice mails are transcibed and sent as a text, with the included audiofile. It works over the internet, so you can have multiple phones with the number, and you can use your computer for the service as well.
For data, I use jmp.chats data only esim. It's $7/year + $5/gig but the data never expires.