JF - The problem is that it's a lot of trust to put in a concept that is coming up to 18 years of serious-money development and $90 billion in SDD, with 90 production aircraft delivered. "At this stage" - in those terms - you should expect the design to be showing strong signs of maturity.
But even leaving aside engine troubles of the moment, it has yet to reach any form of IOC, fly with more than a few external stores, land on an aircraft carrier, deploy consistently away from main operating bases or be cleared outside a very restricted envelope for service pilots. It's also currently operating at 30-40 per cent readiness rate.
Last edited by LowObservable; 11th Sep 2014 at 12:13.