I think this is going to be a pretty short post.
I've been doing A LOT of phone screens with software engineer candidates in the last 2 months. I've been getting frustrated with just how many candidates get past the initial phone screen stage (with me) only to realize that when we put a laptop in front of them, they are pretty bad at writing code. Of course, the ability to write code isn't the only thing we care about when we interview folks; however, no matter how excellent your soft skills may be, if you can't write code I won't be able to hire you.
I've only conducted 2 phone screens while utilizing CoderPad but OH MY GOSH - I totally should've started doing this years ago. Even though I've just started having candidates write code during phone screens, I already know without a doubt that I'm going to continue to do this. I don't get a lot of time to write code, look at code, comment on people's code, etc. these days so for me to interact with candidates while they write code has been fun for me and I think will continue to be fun (hopefully).
All that is to say - if you're having to phone screen developer candidates you should STRONGLY consider having them write some code.