Just read Dan K's post from May.
My 9 y/o MacAir cpu and memory became overwhelmed with newest OS update. Read a review of Lenovo chromebook and bought for $400, vs about $1,200 for latest version approximating a MacAir. It is certainly heavier and different but am growing used to it. Its processing is much better. I don't like that I cannot 'install' (afaik) a separate adblocker, but its built-in adblocking is passable. It is only my portable machine. I have two powerful desktops for real work.