I just started reading the book "Conversations with Mani Ratnam", by Baradwaj Rangan (film critic) and it has many references to Ilaiyaraaja. But the most striking one, which I think might appeal to those Ilaiyaraaja-fans who hate Mani Ratnam, more for ditching him rather than for his work, is this:

I still think Raja is amazing. I think he is a genius and he will always be one. Till today, I think some of the best music that I have grown up with is Raja's and till today, there is nothing that moves me as much as his music. I have no issues on that and I've never had a problem, really speaking, with him.

Mani Ratnam however, diplomatically avoids delving into what exactly happened (because it seems to be a rift between producers & Raaja) .