It was only night two of the tour, so I wasn't too shocked or disappointed by any warbles or off-notes. To me, they all had them a bit during their solos, and I expect that sort of thing at a live show--let's you know it's not being synced. And truly, it was so damn hot in the audience, to say nothing of what it must have been like on the stage, under those lights...that humidty has to fuck with the voice and breathing a bit. As well as all the bug swallowing.
...that said, Glenn's voice has changed quite a bit since the 70s. The tones he hit then he can't hit anymore--it's hard for a man to maintain a tenor like that over the years. Aging has probably affected it; on-and-off-smoking, medications. And I'm sure the sinus issues/surgeries he's had over the years due to aftereffects of drug use have affected the timber and tone of his voice, too. But I thought the new arrangements and powered pitches suited him and the songs well. I think he's had the most songs added back into the setlist that feature him on solo/co-lead vocal, so it has to be a bit more vocal pressure on him and his voice. As he settles into them, it will all iron out.
(I felt sorta bad when he said after his warm reception during band intros that he's been feeling "fragile" lately and he appreciated the love--is this his usual schtick, or is the poor man truly feeling down and out? C'mon, over, Glenn, I'll cheer you up.)
Not at all to say he was the "weak link" in the show that night--in fact, I thought he picked up steam, vocally, the second half (he ruled "Heartache Tonight) , while poor, sweaty Don seemed a bit beat by the time HC and Desperado came along (the poor man needed to take off that 3/4 sleeve, non-breathable fabric-looking work shirt--he was soaked by show's end!) And you could really hear him anchoring the harmonies in BOML and HC, among others.
As for the people sitting most the show--I've been to shows at the Marcus where people have stood the entire time, and others where people choose to sit and relax. You can never tell. Toward the end my section was standing a bit more, which was nice. There was an uber-wacky woman by herself in front of me who stood the whole show and flailed about, which pissed off the bank of people sitting in wheelchairs behind her seat, who said she was obstructing their view of the stage. So they kept yelling at her to sit down once in awhile, then an usher would come over and talk to her, and she'd pitch a fit and keep be-bopping about everywhere. I wasn't in their line of sight to obstruct their view, but it made me paranoid to strand too much! Finally at the end everyone was standing so I felt I had nothing to lose by getting and getting down to the music!