Some F-15s out there are 25 years old or older. I think it would have been more of a surprise if the F-15s had outperformed the E-Fighter. A better comparison might be the latest against the latest.
Read some comments about the E-Fighter and the F-22 Raptor from someone who has flown both.
http://www.af.mil/news/story.asp?storyID=123009594 http://www.af.mil/news/story_print.a...ryID=123010102
Before you go screaming that Gen. Jump (U.S. AF COS) is obviously biased, read the comments and you'll see that he says he believes "the two aircraft are running neck-and-neck". They are different aircraft with different roles on the battlefield.
Here's another article, "Measuring the F-22 Advantage - (compared to European fighters; Rafael, Eurofighter, and Gripen?)"
http://209.157.64.200/focus/f-news/1403808/posts