The search function in this forum is your friend. There are plenty of threads where people shared their experience, including myself.
If you can’t find an answer, please be more specific indicating your model. Haiku’s experience with a Mac may vary, a lot.
However, I can tell you that models until 2015 work but usually Wi-Fi, special keys, ALS, keyboard backlight and graphic driver do not work (framebuffer fallback is needed with no brightness control).
Hmm besides graphic drivers… Haiku does not have intel video drivers form *BSD? Are there even graphics drivers when what only does Haiku have for rendering isn’t even at OpenGL level-- 2D rendering only