I've seen them both live. Wall tour 2010 and Rattle That Lock tour 2016.
Waters decided to do a second tour with pre-1983 material and a third with mostly pre-1983 material. Also his new "Us and Them" tour is going to be 75% Floyd stuff and 25% solo. This means that he is not happy with his solo records or that people don't know him as a solo artist, so he's depending on the Floyd name to get a big audience. Don't forget the title "The creative genius of Pink Floyd", because "One of the two singers and one of the bassists of Pink Floyd" just doesn't cut it. I agree that the Wall tour was astonishing, but he's done it before. Upgrading the effects to the 2010s and adding a couple indifferent songs, is not bringing the Wall up to speed. It is just him trying to be relative again, because no one's paying attention to him, and I mean this lyrically, not as an artist.
In the meantime, Gilmour is just playing guitar. And a little bit of singing. Yes, he's enjoying his time while he is alive, he's not giving a dime about politics (I disagree but that's what he wants) and he still promotes his solo stuff. I didn't like On An Island or Rattle That Lock, but seeing him do some Floyd stuff was awesome. But he is not stage effect heavy any more. He's too old for this poopie, plus his solo stuff don't require effects like Waters' shows.
I don't like their solo works. I love them up to Animals, because that was the last album they produced as a band.
About that Gilmour and usurping, you have your info wrong. Gilmour was a friend of Barrett's and he was actually the person who showed him a lot of stuff on the guitar. Waters, who wanted to be famous, decided that an unstable Barrett was a liability, so decided to bring in Gilmour to cover for Syd, while Syd was on stage, without singing or playing guitar, just standing there, staring at the audiences. And guess who decided to kick Barrett out of the band. Yep. Waters, not Gilmour.