I have three CZs, one of them a 550. I don't own an Icon, so can't say that I can compare it objectively.
My first CZ was a 550 Varmint Laminated in .22-250. Easily a 1/2 MOA rifle to 300 yards. The 527 Varmint Laminated in .223 that I added later is even more accurate. I wasn't sure how well I'd like the single-set trigger, but it's grown on me. While the actions haven't been as "glass smooth" as my M700s have been, each of them have become much better with after a hundred or so rounds through them. Extra magazines aren't inexpensive, though I've not found it necessary yet to purchase spares. Classic Mauser action - you really can't go wrong.
I don't know much about the Icon, but if I were in the market for something in a CZ550 or an Icon, I wouldn't hesitate sticking with CZ.