Okay so if you are on 6.13.219 (latest GB ota), you should be able to install 6.16.208 as long as you havent deleted any system apps or anything like that. Rooted or unrooted it should work.
From what I see OTA Rootkeeper may or may not work if going from 219 to ICS 208, so be careful.
If you are on 6.16.206 and want to update to 6.16.208, we have to wait. An installation over 206 is not allowable by the recovery, as it says in the "Unstuck 200 > 206" thread, it searches for the 6.13.219 files, and information of a build.prop, etc... in which the installation will fail. I can't try the method used to Unstick us because;
1. I don't have the 6.16.208 kernel (which I need immediately)
2. I don't wanna brick my phone (lmao);
so I will try it once I have the 208 kernel though but if anybody has a different method please post.
Rootkeeper worked for me going from 219 to 206, so it should work if someone is going from 219 to 208. What we don't know is will rootkeeper work going from 206 to 208.
.219 (GB) to .208 (ICS) is that you are using the OTA "update" process which just updates your system.
.206 (ICS) to .208 (ICS) if possible using the same .200 (ICS) to .206 (ICS) process....your are fastbooting your system partition and a few others wiping them back to stock then updating a semi stock system to .208 (ICS).
I don't see OTA rootkeeper having the ability to retain root on a system that is fastbooted with stock images.