Try to find out what maths textbooks that your school is going to use, that way, you won't waste your money if your school is going to give them to you.
They didn't change anything in terms of the questions in the exercises but they've only add on a few more "challenging questions" in the challenging section. Other than that, they've just made the book thicker than cambridge for the latest edition.
Coroneos has great explanations and good questions too. Couchman is alright i guess... but cambridge and fitzpatrick is all you need. (and most importantly, PAST PAPERS!)
Like Fitzpatrick, Coroneos is separated into 2 books, 2u (pink and huge) and a 3u book (orange). So if you want some more...