How many schools to apply early action?

Hi, I am a rising senior in the midst of college applications. I am currently applying early action to MIT and Caltech. I am also applying to the University of Illinois at Urbana Champaign and the University of Michigan at Ann Arbor, both of which are early action as well. My question is, should I apply to all 4 schools early, or is that too much?

My D applied early to every school that offered it. There is no down side if you can take your time with the applications and are happy with your GPA/scores.

Yes, if you have time over the summer to fully prepare a solid application, having them out of the way is a big relief once schools starts.

My D had 6 of 7 done and waiting until Christmas break to do the one due 1/1 that had only binding early applications.