I have taken deer with both bullets and prefer the XTP.
The last deer I shot with the SJSP was hit right behind the shoulder around 45-50 yards. The bullet acted much like a FMJ. It went right through both lungs and out the other side. Sounds good huh? Well, there was no expansion and very little terminal damage. It really was a clean, pass through hole. The deer ran about 150 yards and piled up, leaving a very little blood trail.
The deer I have taken with the XTP have all ran less than 30 yards, if they didn't drop on the spot. All of the XTP's have had nice terminal damage and exited. They seem to be a better "deer" bullet than the SJSP in my opinion. The performance has been good and the XTP's have not let me down.