Been with Sprint for many years, mainly do to the 24% work discount. Still with two phones the bill comes out to $73 with taxes on the $69 family plan.
Since we are low usage under 500 minutes and just a few text messages. I bit the bullet this weekend and transferred both my Sprint phones and numbers to Ting. Total bill should be around $30.
Off contract. I am still using an old Katana flip phone. Had it for 6 years. Wife has had her last phone Lotus Elite for about 2.5 years. No trouble moving both phones over.
Ting offered a contract buyout at one point not sure if they still are.
If you search the site they have a white list of phones that can be moved over. Have some that are officially supported.