Unfortunately, I don't think this is a Wayland only issue. After I upgraded from 17.04, I've found lag/sluggish response with gnome-shell under both Wayland and Xorg. It does seem to be a little worse under Wayland.
In my case, after a reboot, all is good for a while, but things slowly degrade and after a few hours, switching between virtual desktops or moving windows gets slower and slower. When the lock screen kicks in, after hitting a key to bring up the password prompt, there is a definite lag i.e. on a couple of occasions 15 seconds before the lockscreen wallpaper is cleared and the password prompt appears.
This is on a high spec machine i.e. 12 core i7 3Ghz with 32 Gb memory. I'm using the default oss graphics drivers (I have a nvidia gforce card, but not using the nvidia driver as it is not compatible with wayland).
I did not have these problems with 17.04 and the gnome ubuntu remix.
I've now installed MATE and seeing if that works better as the gnome-shell gets sluggish enough to be almost unusable unless I reboot every few hours.
Using journalctl to look at the logs, I see a lot of gnome-shell related errors and warnings.
All pretty disappointing. I was also unlucky enough to run into the fwupd bug related to some Logitech keyboards, so had to change my keyboard to even get 17.10 to work!
Best Answer
I followed advice from answers to the queston How to enable natural scrolling with mouse in 17.04?. In my case removing xserver-xorg-input-synaptics and restarting did the trick:
sudo apt remove xserver-xorg-input-synaptics