We've never had Imo's and on our first trip to St Louis we wanted to try it since we were told it's "St Louis" style. It was inexpensive, and I'm glad. I did not like it at all. It could be the marinara ... I thought it was too sweet. Also, I love thin crust, but this was ridiculous.
In any case, the hubby and kids all seemed to love it ... Different strikes for different folks :)