I'm so split on this thing I haven't found the energy to quantify anything with a post since they announced the go-ahead for the program.
Either way you slice it, I feel like it's still a hand-out for Boeing who had been struggling to secure contracts lately.
Are there aging C/D models out there that should be replaced ASAP as our principal (numerically-speaking) front-line air superiority fighter around the country (and indeed, the world)? Sure.. however it's almost 2020 - do we want to be replacing these aircraft with designs dating back to the '70s when the alternative is something straight out of the future? I really don't think so. This argument is compounded by the FACT (yes, I said it.. fact) that current-build F-35A's are rolling off the line cheaper than this initial batch of F-15X's is going to cost. Everyone throws development costs into the per-aircraft cost, so it's only fair that the 15X takes the same hit initially - actually it's even more fair since it's INCREDIBLY UNLIKELY that this plane sees large production numbers. Actually it's impossible.
Plus side? Okay it's got a different assembly line - which conceivably isn't maxed-out like the F-35 lines are, but WTH - it's going to take years to get any sizable number of aircraft out of Boeing's lines for our jet (and even then, that's after R&D/dev/testing schedules and delays). By then you could have dumped the same amount of money into maximizing the F-35's lines, bringing down costs for contracts that the USA (and many other countries) are already investing in, PLUS the aircraft you're trying to supplement and/or replace with this F-15X budget.
I don't even want to get into capabilities - there's a very small list of things the 15 can do better than the 35. Most people in this thread focus on utility-type missions such as ASAT and missile trucks... yet we're replacing C/D models which currently fulfill the role of air superiority fighters. In an air superiority role, these X/EX's would be shot down at an alarming ratio versus F-35's, which is my point at the end of the day. Replace the air superiority fighter with a plane that's better at it. If you need to do something else - get something else to do it, but don't keep pretending just to keep the program alive.
I'd be ALL IN 100% if the thing cost $60m or so (aka significantly cheaper than an F-35) - the price would justify the lack of capability if we could offset in numbers and flexibility - but it's just never going to happen.
I even talked to a bunch of ANG F-15 C drivers at Joint Base Andrews air show a couple months ago when we flew the Avenger in there, and they were REALLY excited about the 15X program, but were the first to admit that there isn't TOO much of a speed advantage once range (ie drop tanks) and external stores or tanks were thrown into the equation - versus the F-35. There is some advantage though.
Even got to hang out for a bit... (this thing was built the year I was born in 1984! Looked immaculate for what it's worth though.)
For some reason the img won't display.. http://hickoryhillwv.com/wp-content/uploads/2019/06/IMG_3990-e1560375330681.jpg