Are MTX brake pads thicker than OE stock brake pads?

No.

Surprisingly all brake pads are the same thickness, and our brake pads mimic OE dimensions as tightly as possible. 

If you are experiencing rubbing after installing our brake pads, this can be resolved by pushing your caliper pistons flush with the caliper body. Even a hair out will make a difference. 

How to fix the rotor rub? 

Either put the old brake pads back in and carefully use a flat-blade screwdriver to pry the brake pads apart (which will push the pistons back in). 

Alternatively you can use a plastic tire lever to slowly pry each piston flush.  

Again, our brake pads are the same thickness as OE - the rubbing you may be experiencing is absolutely the protrusion of the caliper pistons.