I've watched a lot of the online videos - few thoughts:
Nic is killing it. Sounds great - hits the patterns and the timing is very tight with the band. Do not underestimate how difficult that is to do. Yes - he isn't playing the small subtle fills and patterns that his dad did, but his dad had years and many performances to get the muscle memory locked so that he could play with the unqiue patterns. The power is there and I'm happy as hell we got Nic on the kit. No disrespect to Chester, but his drumming from 92 onwards wasn't very good.
I love the backup signers. Kind of wish they were more forward in the mix, but hearing harmonies in Carpet Crawlers is a breath of fresh air. Kind of wish Genesis had them in 2007.
The key changes are not subtle and I totally get why they do it. As a vocalist myself - you have to change the key for your vocal chords. I sing many songs down half a step or so as I can't hit the high E notes like I used to.
I listen to the clips in my car without seeing the video. No Son of Mine, Carpet Crawlers, I can't Dance and a few others sound great - can't tell it's not 2007. Others Phil struggles with, but I struggle getting out of bed at my age now - so it's all good. Rock on.