^^ The PSLGT is a completely different racquet so even at the same tension they will play differently. My personal advice would be to start at the lower range first, maybe 52lbs. Coming from the PST you are used to more power from the frame that you won't get with the PSLGT. Dropping the tension will give you back a little more. Also, X-One plays pretty stiff even though it isn't.
I use TF XR1 at 50lbs mains and 48lbs crosses and the racquet still plays nice and crisp with excellent control.
3X PK Ki5 315 ::: 4X PSLGT and 1X PSL ::: 2X PSTGT and 1X PST
MCS mains and PPA crosses