I think the dynamics and energy felt a bit off. LB's intense energy is certainly missing and it almost felt like Neil was singing in Lindsey's range/style a little bit, trying to bring the same edge to the song.
I think as they go along he will relax and just be Neil Finn and bring his own unique energy. He has so much experience and talent and he'll find the right approach and balance and just be himself, using that to create a new chemistry that's different but just as valuable and interesting as all the others who have come through the band before him. He's NEIL FINN, for goodness sake. As soon as he sets himself free, the way Stevie, Christine, Lindsey, Mick and all the others (past and present) are just their own individual selves (which, combined make the whole), when Neil just starts being Neil, then it will be come the "new" Fleetwood Mac - for better or for worse (or for just different).