Hi. I have had difficulty in controlling of PMDG 737 NGX on ground in FSX . Unlike the other PMDG planes I fly with ( MD-11 , 777 and 747 ) , 737 on ground is very very sensitive to both steering tiler and rudder inputs specially during takeoff rolling and landing after touchdown. Keeping it in runway center line during takeoff and landing is very harder than the other planes.

This is an unusual complaint, I assume since you mentioned tiler that you are using 3d party stuff such as FSUIPC to calibrate and assign axis?  Run a test without the 3d party stuff, assign the axis in FSX and calibrate full scale and center and set up a small null zone and see how that differs from your current setup.