I have not thrown the Throttle. I have the Phenom, and after throwing it side by side with a Throttle, the Phenom gets down the lane much further. That is the major difference between them. The guy that was using the Throttle was playing straighter than I was, but that is primarily because of the difference in our games.
I really do not feel you can go wrong with either of these for oil. What I would take into consideration is how you bowl. If you like to play straighter then the Throttle would probably be better---------if you like to send the ball out, then go with the Phenom. IF it is TRUE heavy oil----which in my opinion would mean heavy head oil and no backends, then you are probably better off the Throttle---or have the Phenom drilled to roll early.
goodluck