The Master Magician makes a good end to the series, bringing Ceony to the end of her apprenticeship, and her relationship with Emery to a satisfying point. If you found everything a bit too fluffy and light, and Ceony’s abilities a bit too good to be true, then this book will probably tier up with that — she’s now able to do pretty much anything she wants, and does, having mastered all other kinds of magic in the meantime.
I don’t think it was the best written trilogy ever, but I enjoyed it, particularly when I wanted something pretty easy and fast to read. There are some horrific bits (i.e. when Ceony faces psychopathic magicians), but for the most part… yeah, just a really easy read.