With his Brokers license, he is trusted to a higher level than a typical real estate agent. This means you are working with someone more dedicated to the trade deemed by the state of California. His C.R.S. certificate means he did additional education to learn what it takes to have a more smooth transaction, with fewer pitfalls, and overall seems like less work for you.
The C.D.P.E. certificate he earned makes for a higher success rate for short-sale transactions.