Madison Sully wrote:
Based on the pictures, it looks like you brake harder with the rear than the front brakes. You can see machining marks on the front rotor still, where the pad makes contact. The rear rotor shows no such machining marks.
Are you left handed by chance?
I would think moving to sintered pads for the fronts may help, but only after bedding them in to the rotor. Beyond that, swap front and rear hydraulics if you are indeed stronger in your left hand. Gripping the brake lever more out toward the end would help increase stopping force too.
If none of these work or are unappealing, the smaller diameter piston would increase stopping force, but keep an eye out for squishy brakes; that smaller piston will displace less brake oil, so your caliper will have less throw and could cause the brake lever to bottom out on the handlebar.

I am in fact left handed. Before I got my rear pads changed I was only ever using rear because the CBT centre drummed it into me that front brakes are very dangerous so I was scared of using them.
Since the pad change (few weeks ago) I finally realised that I needed to change my braking, And now I use majority of my braking with the front.
The main reason why I'm asking for calliper upgrades is because both levers are loose and have a lot of travel (spongy - yet i've bled both lines with 500ml in each just to make sure there's no air), I prefer levers solid and more responsive - is this a calliper upgrade or down to something else?
Thanks for the suggestion for sintered pads, i'll get them asap along with a torque wrench.
Cheers guys!