Meaning does anyone ready a model and then wait to activate them so as to take advantage of consecutive turns and some of the unit special abilities?
I have done this a couple of times but have never seen anyone else do it.
It is a common ptractic in our community 
Same in mine. There are a few abilities, that only trigger when you first ready some and then activate the units.
We have a small community, but most of players do it fairly often.
- The two most common use are turn one for movement. We play terrain heavy, and occasionally see turn one and two pass without real combat, so group moves get to be a thing.
- objective claiming. Usually during objective screw scenarios, we will activate multiple so we can clear and claim, or claim and block an objective.
It depends on the units you use, most units don’t have any special abilities that allow you to take advantage of that.
One of my friends plays Survivors and runs a Minuteman heavy list, so he uses the Minuteman ability to activate another Minuteman a lot and even with the Quick Action penalty, he can chop up opponents with shooting.