Drowned city Investigator expansion: Cop or naw?

I am a new player who managed to get my hands on TDC campaign expansion and am excited to play it but am wondering if I should try and pick up the investigator expansion with it? I only have the chapter two core set plus Marie and Miguel but I'm thinking about adding this. I've done some research and some of the characters look pretty complicated and/ or have very niche specific abilities/ traits. Should I pick this up or just stick to chapter 2?