I love Miro so much that I found it hard to write about him in a critical fashion. It's a bit like trying to describe one's favourite melody and explain what's great about it!
I did manage to, eventually, write a fairly substantial piece about some aspects of his paintings here - https://medium.com/signifier/head-to-toe-with-joan-mir%C3%B3-eeccda8096c3 - which may be of interest? I hope it goes some way to explaining what I admire about his art...