This was seriously my favorite title in the series. Not for the story or even the online play, but for the fact that I could play in a bot arena and play around with all the weapons and equipment without having to level up. This is all I really want from a shooter and that's what I was finally given with ghosts.
Black Ops had the same arena option, which I, too, absolutely adored. It reminded me of the good old days of Perfect Dark on the N64.
However, I bought myself Ghosts with the special edition, including season pass and many extras, as a birthday gift just when Advanced Warfare had come out, after weighing them both for a while.
I was thoroughly disappointed. As a long-time Call of Duty fan (played since the first one, but became a big fan with the first Modern Warfare), I feel it's easily the worst game in the series, and while it's known that many people object the multiplayer, my issue with it includes the Campaign (still the most important aspect for me) which I found so dreadfully boring that I've put it off for slightly over a year one having painfully dragged along for about two thirds of it only to leave it as of yet incomplete.
They seriously dropped the ball on that one.
Curiously, Advanced Warfare hasn't very well-received either, but I found it one of the best in recent years, and a fresh breath of air among the similarly set Black Ops 2 and 3.