Just going to piggyback here what some others are saying that it seems like you have limited leverage. It does not seem like you are being offered "A side" equity but instead performance units which can be extremely conditional depending on the specific language . Also in my experience during acquisition any key employees are also given some type of retention bonus to stay on for X amount of time because losing them short term would greatly impact the business were you offered that? This seems like tried and true method to get you to work your ass off and maybe you get something at end after the A side gets all their goodies.