Diablo 300 is good for the money but its not even close to being the "best" integrated. Higher priced ones like Dag Momentum will smoke it in every possible way...but its 2.5X the price. Dartzeel 8550 is another one that is above and beyond the Diablo 300. Im sure there are PLENTY of others if you have the coin. (T+A, CH Precision etc)
You can check the thread mentioned in the above post to see how the DAG Integrated fared against the Diablo 300 in a shootout. It wasnt pretty for the Diablo.