If by that childish 'Microsoft Flight Simulator'
spotter-geek appellation 'Dave B', you're referring to the F-35B, I think you'll find that it's a STOVL aeroplane, not a CTOL aeroplane such as the F-15.
However, the F-15 has had the benefit of many years of constant development, whereas the F-35 is at the beginning of its service life. So the new F-15SE is likely to be an exceptional aeroplane.