Kernel 4.15 must be about to release to SID.. there are no RC candidates at all in the SID repos
I was going to update the ISO's today but will wait now for these to release
So far 4.15 has worked great for me. I went through the last few of the rc releases of 4.15 and had no complaints. Mine is only modified because of some of the laptop things, and getting rid of the things I don't need for the laptop...
(http://en.zimagez.com/miniature/20180203c.jpg) (http://en.zimagez.com/zimage/20180203c.php)
Running 4.15.0-nixnut which is really just 4.15 mainline...