Tigana is a very deep book, with a number of themes and rich language. I listened to the audiobook narrated by Simon Vance, which was excellent, but I would recommend you read it in print to enjoy the writing better. Tigana is high literature. GGK takes his time in description, tweaking at strings of emotion the entire way. This can be harder to follow in oral form, I think.
The setting and story are complex and imaginative. Do not read the author's afterward, spoilers lie here. Highly recommended.