I was very sure they have messed up a perfect thing that was lxde, but 5 minutes of using lxqt and configuring it, I had all the good bits of lxde with a lot of awesome new bits.
I was sold on it until it (18.10) booted to a black screen reboot loop and basic debugging didn't resolve the issue. I didn't have time to nail the cause but it could have very well been me tweaking config.
I am back on 18.04LTS but will be upgrading happily to lxqt at 18.04's EOL.
I've had a couple failed Ubuntu upgrades recently, with similar behavior ("oops, you can't boot anymore, sorry!"). And I only use it on one fairly boring machine doing fairly boring things with it—I don't tweak anything.