So, 9 months later and things haven't gotten any better. My wheel started behaving like the video in the OP and I sent it back to Thrustmaster about a month ago for repairs, hoping that would finally solve my problems. They said one of the ffb engines/motors had gone faulty, they replaced it , tested it, and all was good. I got it back last week, first thing I noticed is the screw hole where the desk clamp screws in was crooked and now I could barely open the clamp wide enough to fit on my rig. I managed to get it on there, but it was a lot harder than it had been previously. Also, I noticed that the wheel now wobbled if I pulled on it, like the connector between the rim and base was loose, but it was fully tightened. Not a huge deal, but shoddy for sure.
I get it hooked back up and it feels great! A nice, smooth weight to it, I can feel suspension moving, I can feel tires scrubbing, I can feel it get lighter when understeering but it still has some weight and is telling me what my tires are doing as they lose grip. Then after a couple days I notice that when understeer happens it's going really light again, and a day or two after that it's gotten so bad that at the first sign of understeer the wheel just goes limp and flops over like someone unplugged it from the power source, it's a miserable feeling. Now, any time I move the wheel past the 9:00 or 3:00 position the wheel just loses all of it's force/resistance and feels like crap. It felt great last week and I haven't changed any settings, but now it's rubbish (happens in all of my sims).
You can kind of see it in
this video, once the wheel goes past 9:00 or 3:00 the wheel just flops over and loses all weight/force/resistance. I'm back in contact with Thrustmaster, the gave me a couple things to try when I get home this evening, but I've pretty much lost confidence in them and their product. If I can for sure determine that this is a problem with the T300 and not with my PC then I'm probably just going to toss it in the bin and take advantage of the CSWv2 Black Friday Deal next week.