I agree. The "911" feature is worth keeping the Frontier landline for me living in a very remote area. I call 911 and the sheriff knows immediately what my address is...as I'm grabbing my 10 gauge. Try calling 911 in an emergency with a cell phone and giving necessary information in a panic as 2 drugged low-lifes are crashing through the front door...not!
Landline quality is superior. I have maintained my Frontier landline for backup use and use a Verizon Wireless unlimited calling package for most of my calls with the Droid X. I also have the Iridium satellite phone in case the world turns crazy.