I'm still lovin' the siggy but discovered something recently...
While reviewing some videos shot during the holidays with this lens, it quickly became evident that the funny creaky sound on the video came from this lens while focusing. I can't hear it while shooting but it is definitely audible on playback.
Quite comical for now. We'll see how long it takes before it gets louder.
There are a few others who have a similar symptom (https://photography-on-the.net …p=11456258&postcount=4116) - myself included. I will be shipping it to Sigma next month to have the squeak corrected (have a few more shoots in the meantime).
They have a very long warranty so not concerned