Just beware that some of the realtors through the USAA program may not be doing you any favors when it comes to closing. Two years after buying my house and getting ready to rent it out my property manager who is also a realtor did a courtesy review of the sale and pointed out various costs in which he thinks the realtor could have negotiated much better to get the seller to have paid, but in my inexperience as a first time home buyer I wouldn't have known any better.
His other POV was he gets business based on his high reputation and word of mouth as opposed to having to pay USAA for customers.