I like the silent eagle concept. Remember, stealth only has to be good enough to let you get close enough to shoot first and then escape. For an interceptor and air defense role, the F-15 is still outstanding especially with the newer engines and avionics packages. And the upgraded F-15E airframe which is now standard for all F-15s, the airframe is extremely strong and durable. I saw video of an F-15C that pulled about 12Gs and although it flew home, the plane was destroyed as it broke the motor mounts and badly bent the airframe. A friend of mine about 16 yrs ago pulled 12.5Gs in an F-15E and 2 weeks later the plane was returned to service after inspections and replacing a couple of cracked vent grilles.
So the plane is strong/durable, has a proven ability to withstand combat damage (including one that flew home after a direct aim-9 hit oops), is extremely fast especially by modern standards, and with upgraded avionics/radar is still world class in terms of systems and sensor integration. If anyone buys the extra outer wing pylons that the USAF never bought, the plane can carry 10 missiles in an air defense configuration. The plane has the whole package in terms of combat capability, with the exception of "stealth". Well, the silent eagle program really cuts down the RCS to the point where it may not be first into a modern air defense system, but it is more survivable than before and would be much more capable as an interceptor or strike package escort due to its speed and lower detection range after the low observable treatments and modifications.
Plus... mach 2.5. Seriously. And it was the world's first supercruising fighter, no matter what they say about the F-22. Even the "small" motor -220 versions could go supersonic in mil power when completely clean, and the -129 and -229 versions had very appropriate warnings in the tech order about inadvertent non-afterburning supersonic flight even with some combat loadouts.
So, yea I'm a fan, and sad to see both the US and Korea pass on the opportunity to refresh their fleets with very capable and updated F-15s. The Saudis know that the whole world fears the F-15E, and that's why they recently bought another couple dozen and also bought upgrades to their F-15S fleet, alongside their purchase of some Eurofighters. Singapore bought them too, when they decided that they needed a heavy fighter instead of a bunch of vipers or other little fighters. I don't know any F-15 operators who have been dissatisfied with them, so I remain a fan of them as a cost effective no-holds-barred interceptor and strike fighter.
Plus, the radar. My god. It's incredible. The capability that the radar alone brings to the fight still makes up for the plane's size and RCS for any use not involving penetrating the air defenses of a superpower on day zero. On night one though, beware... An airplane flying Mach .9 at 100 ft at night in all weather is hard to intercept no matter what you're chasing it with.