Just finished laying over 1,800 sq ft of grooved South American hardwood decking. We used several deck clips, including Tiger Claw. For TREX, however, I have used their Hideaway Hidden Fastening System. It is designed specifically for Trex grooved deck boards. This is their proprietary system for fast and easy installation. The result is a smooth, fastener-free deck.
The Connector Clips are black, stainless steel fasteners. The boxes come with square drive bits that do not slip.
Check them out: