I disagree ^
It was Dec 2008 - so 7 years ago this month - that I saw Weiland perform in Chicago (where I got to meet ScottLoungefly, Christie, and Cori - AND where my husband proposed) - and Weiland was out of his mind. He was incoherent and attempted to first tear down a sign hanging on stage before giving up and climbing it, then throwing his microphone down and walking off stage.
He hasn't been lucid since well before the HIG tour.
I think I remember him climbing, or struggling too, climb a speaker or something during 'Barbarella' and not having much success. Then threw down the mic and whatnot before closing with the encore. In comparison, I saw him stage dive at the Riv four years earlier with Velvet Revolver and he had no problems.
Last time I saw him perform was in 2011 in Hammond, Indiana with Dean, Rob, and Eric. In terms of performance and being 'all-there', that was I best I saw him since STP reunited. He looked good. The other times (the aforementioned HIG show and a May 2008 gig in Chicago) he was lost in the clouds.