I am not aware of any studies that have focused on precisely how the "flavor" of El Nino affects its impacts on global averaged temperature. I note that regardless of whether this event is centered more toward the east or west, if the event is moderate-to-strong, then it likely will have a significant impact on global temperatures. I believe that the longitude of strongest warming would be, at most, a secondary effect. If I could speculate (again, I'm not aware of any studies), then I would think, all else being equal, warming in the east would have a little less impact than warming in the central Pacific because warming in the eastern Pacific generally has less impact on atmospheric convection due to the cooler sea surface in that region.