Strike Eagle - all day long / hands down / no questions.
While the Strike Eagle may be a air superiority fighter modified into a ground attack / strike fighter, it is still a superior aircraft to the "multi role" Super Hornet.
The F-15 was designed with the ethos of being the best of it type & was for a long time the superior air superiority fighter - it still maintains 99% of this capability, with additional strike capability.
On performance the F-15E eats the F-18F with much more power & larger wing area, although the F-18F does have the flexibility of operating from carriers!
I am not sure on the tight in / dogfight performance comparison of these aircraft, the F-15 has the power & flying surface, but the F-18F may suffer less from AOA limitations ??
I am also not sure on the radar fit, the APG-79 as fitted to the latter F-18F is more advanced than the APG-70 of the F-15E, but is apparently suffering from some pretty serious software issues - which I suppose time will sort out though ??
The F-15E is still the horse I would be choosing to ride though.