The publisher's review of the second edition states, "More detailed presentation is given of elementary topics, to reflect the knowledge base of current students."
I think that is a disingenious way of saying the first edition discusses elementary or introductory topics insufficiently to prepare the readers exposed to this for the first time for the remainder of the book. That certainly was my experience in hindsight for I was not able to get sufficient feel out of the first two chapters, and as a result the rest of the book was tough to follow. And not having answers to ANY of the exercise problems is a serious impediment. However, later I bought the book by Churchill & Brown, and after reading its first 5 chapters, I was able to follow Priestley pretty easily. And I appreciate Priestly's incorporation of elementary topological concepts in proofs of Cacuchy's theorems, which I think will be helpful for those taking topology later, or some interesting formulas obtained by contour integrals. Later on I did all of the prbms in Priestly and once I did more than half of Churchill & Brown, which has answers to odds, the lack of answers in Priestly did not bother me as much. (maybe that's saying a lot about C & B. But C & B is at a mathematically lower level proof-wise but would be more suitable for physics/engineering readers as it has more formulas and their applications than Priestly, and I like C&B more from that perspective. Reading both books is the most balanced approach.)
If the first two chapters of the first edition of Priestly were replaced by ch's 1,2,3,5 of the fifth ed of Churchill & Brown and has answers to odd-numbered prbms, I would give it 5 stars for a semester course (insufficient number of topics in Priesley for a 2-sem course though I can imagine C&B being a 2 sem course) b/c I appreciate the rest of the chapters once I obtained the background from C&B. Otherwise obtain the background from C&B BEFORE taking Priestly. I don't know how well the defect was remedied in the second edition, but the reviews are not encouraging.