Not trying to pick a bone at all but if I had watched a Genesis video from 1973, 1976, 1980, etc., at the time, should I also have not judged the performance and just "see them live"? I have tickets for Genesis too this time around, let me clear. But my level of enthusiasm is at about a "1" on a 1-10 scale, after seeing these videos. You can delude yourself into thinking that they sound great; they don't unless you're tone deaf. Phil Collins can't sing anymore, period. His timbre is horrible, he's off key a good chunk of the time and he can't sing to the tempo (just watch the damned videos). Yes, the visuals are great, yes, the musicianship (mostly) is ok but that's not enough for a professional show that's charging $150-$500 a ticket. Come on! You wouldn't accept this from any other act! Now if you want to enjoy the company of other G-fans and have fun for one night, I get that. But to push the argument that they sound great? Not even close, unless you're completely delusional or your only experience of them live is 2007.
I had all the same reservations you did, I really did. I had seen all the teasers and clips prior to going and I really thought Phil couldn't carry this off. You're right his tone and timing is off. It was a bit painful and worrying at times.
Then I went to Manchester and admittedly I was 10 rows from the front, but they blew my mind. I was literally buzzing for days.
Was Phil a bit off? Yes. Was he terrible? Not at all. Was he trying his best? Absolutely. Was he winning the audience over? They were in the palm of his hand.
The band honestly sounded as good as ever (albeit with undesirable key changes which didn't bother me in the end). In the instrumental sections you could close your eyes and it was the same old band, as tight as ever. The mix/PA was excellent too, total clarity.
I also watched the Newcastle show the other night and Phil had noticeably improved in just a week or so and was in good spirits. I bet by the O2 he would've been pretty sharp.
Remember the concert films from the 70s and 80s were all well rehearsed deep into tours, professionally shot and mixed. It's just not comparable to smartphone footage in the early stages of a tour after a 14 year break at the age of 70!
Would I want to listen to this tour as a pro recording? Well I don't think it does anything the 2007 recording doesn't do. Yes the vocals will be better from that. Or from Seconds Out or Three Sides etc. But this is first and foremost a live performance, and in that respect it 100% delivers.
I think it's good you have low expectations, you'll be pleasantly surprised! I'd reserve judgement a little until you see them.
Of course it's not 1978 or whatever. I wish it was. But it's this or nothing. And believe me this version of Genesis still knocks it out of the park in a way not many bands can.