No I haven't read the novel before watching the movies. But I have always thought that the choice of Barzini and Neri (at least in part I) could have been better. I mean, Barzini doesn't look Italian to me, and when he spoke he sounded nothing like a person who lived among non-English-speakers for so long...

"..Your youngest and strongest will fall by the sword.."

"...now you gotta speak more than one language to pull a heist..." Pudge Nichols

"...Never shall innocent blood be shed; yet the blood of the wicked shall flow like a river. The THREE shall spread their blackened wings and be the vengeaful striking hammer of God..."