I was looking at the Investigator class as a possible base for a new character and ran across the Spiritualist archtype. Thematically it sounds fantastic, the ability to converse with the dead to achieve results in place of alchemy. Mechanically I don't think I understand the trade. I lose my Alchemy and poison handling traits, but only seem to gain access to a small handful of spells - far less than the breadth I could access with extracts.
Is there an advantage to Spiritualist Investigator I'm not seeing? Has anyone tried this archtype out?