I think musically Genesis should be ok. The only doubts were Phils vocals and perhaps his mobility. The music itself i expect will be pretty close to what they've always done,
I simply grudge the ridiculous prices being charged but i also don't like huge venues where the band can be so far away it could be anyone on that stage.
Many people have been asking for a Genesis reunion for years and the guys probably thought this might be their last chance to do it and keeping in mind that they were together as a band for many years so they will have a fair bit of Nostalgia for everyone.
For anyone that goes i reckon you just need to accept that things might be a little different from their last tour but its still Genesis.
Dave