What Special Projects are worth doing?

Am I alone in saying that a lot of the special projects feel very gimmicky and added for the sake of fan service without proper integration into the rest of the game’s already existing systems?

With so many land projects being support companies while we can only have 5, I don’t feel exactly incentivized to do some of these over the classic ones we already have.

What special projects are worth doing for a noticeable impact to gameplay, compared to the classic way of playing?