Many sophisticated investors will not invest without seeing a legal opinion letter. It is also good to get a legal opinion as a double check on the proper setup and operation of the fund. The legal opinion may give you peace of mind, but will never guarantee your deal is totally legal. Change in regulations or change in legislation can make an opinion worthless. Also, look at the final wording of the opinion. It may only say more likely than not to be legal or, even worse, indicate that the deal will likely fail. Be careful of any law firm that guarantees a favorable legal opinion.