A significant key to the Hot Metal design is the use of stronger and more expensive Chromoly rather than carbon steel in the manufacturing process. The stronger material allows for a multi-thickness cup face for more ball speed and distance than the previous 900 Hot Metal as well as redesigned sound ribs in the cavity for precisely tuned vibration and feel at impact.
Since then however the JPX 900 models most notable the Forged Tour have been a huge hit with all kinds of players including two-time US Open champ Brooks Koepka.
The Mini Driver which TaylorMade offered in SLDR and AeroBurner models was a very cool product. It nicely bridged the gap between a driver and fairway wood. For a lot of players that was a perfect fit as the added loft and shorter shaft of the Mini gave them exactly what they needed.