Here’s a comprehensive rundown of the differences between the new drivers.
INJECTED TWIST FACE OR A.I. DESIGNED FLASH FACE
New face technology enhances ball speeds in both drivers, but the methods used to achieve the boost in performance are poles apart.
The TaylorMade M5 driver has been equipped with an Injected Twist Face, which straightens up ball flights from the heel and toe zones of the face. A "tuning" resin is injected behind the M5's face via two small ports, to adjust the coefficient of restitution (COR), or trampoline effect, of every M5 until it is right on the legal limit, resulting in consistently faster ball speeds across the entire face.
Callaway used a supercomputer to create the Epic Flash's new Flash Face, with artificial intelligence learning what worked and what didn't before repeating the process 15,000 times to arrive at the final design. The architecture of the Flash Face was so random that Callaway readily concede a human could never have come up with the design, which achieves hotter ball speeds and greater forgiveness off the face.
HAMMERHEAD 2.0 OR JAILBREAK
Both drivers feature a structural "silent partner" that works in tandem with the new face.
TaylorMade have the Hammerhead 2.0, an upgraded sole channel that sits just behind the driver's face. It has been made more flexible and works in sync with the Injected Twist Face to extract more ball speed, particularly from low strikes on the face.
Callaway's legendary Jailbreak technology is back in the Epic Flash. The pair of internal hourglass-shaped titanium bars strengthen and stiffen the driver's body by connecting the crown to the sole. Jailbreak focuses more energy into the new Flash Face so it can do what it does best: boost ball speeds and maximise forgiveness.
An adjustable sole weighting system features on both drivers, but each has a slightly different take on the concept.
The Y-track of the previous M3 driver has been replaced with an "inverted T " sole track on the TaylorMade M5. Two 10g weights provide up to 1770 unique combinations for ball flight and shot shaping, with the M5's adjustable weighting system able to alter loft by up to a degree, modify spin rates by around 600rpm and produce close to 25 yards of sideways bias.
While the previous Callaway Rogue driver was devoid of any weight adjustability, the Epic Flash gets a sliding weight track that runs along the driver's outer perimeter. A single 16g weight produces minor changes in the driver's centre of gravity (CG) for a fade or draw bias.
Using carbon fibre is an effective way of saving weight and the material has been exploited extensively in both drivers.
A new larger carbon fibre crown has been fitted to the TaylorMade M5, making it 10 per cent lighter than the M3 driver's crown. The resulting weight savings have been diverted into lowering the M5's CG for better launch and greater forgiveness.
The Callaway Epic Flash also boasts a new carbon fibre crown, which is made with a tighter fabric weave that adds strength and reduces weight. More mass was able to be shifted lower in the Epic Flash for additional forgiveness and to optimise launch.
M5 TOUR OR EPIC FLASH SUB ZERO
Both drivers have low-spin models for players who need to drop some rpm off the tee.
TaylorMade's M5 Tour is a smaller-headed option for players who want less spin and a greater ability to shape shots off the tee. The M5 Tour has a 435cc head with a CG that is positioned forward to reduce spin and it is also aerodynamically superior to the standard M5 - the smaller head generates a little extra club head speed. But it still features the same adjustable weighting system on the sole like its big brother.
The Epic Flash Sub Zero is Callaway's low spinning model but its head is the same size as the Standard Epic Flash at 460cc. A permanent sole weight is placed just behind the club face to shift the CG forward and cut the spin rate. A lighter 12g sliding weight is employed on the Sub Zero's adjustable sole weighting system to even up the balance of the driver.
Low spin/low launch Mitsubishi Tensei CK or Project X HZRDUS shafts are the standard options on the TaylorMade M5 and M5 Tour drivers.
Shaft options on the Callaway Epic Flash driver are the Project X EvenFlow, Project X HZRDUS and Mitsubishi Tensei AV.
If you can't split the two drivers yet, there's always the colour scheme to decide for you. The choice is between the black and silver, with red highlights, of the TaylorMade M5 driver or the black, green and gold colours of the Callaway Epic Flash - Aussie, Aussie, Aussie, Oi, Oi, Oi!