Unfortunately, every time this China/Russia comparison comes up, the usual jingoistic "their stuff is crap, we will own them" often surfaces. Often this seems to come from those on, or recently on, active duty. They are not privy to current capability intel I suspect, being well down in the chain of command. They should know what they get to hear is filtered, whether they like it or not.
Being outside of the structure gains new perspective of what intel really thinks of the threat, without the pep talks in the wardroom. Laugh at them at your peril.
For instance, the development of the F-15 in response to the Soviet 'superfighter,' the MiG-25. The Foxbat was believed to be a superfighter that would outperform all current American fighters, leading to the creation of the Eagle ... only to discover that the Foxbat was no superfighter but rather a high speed interceptor meant to kill an American supersonic bomber that never got developed. Was the F-15 an over-achievement to the threat, particularly when the threat was seen to have been (significantly) mis-read and misunderstood? Well, yes. But then, the F-15 had been built to superlative standards, which is why, even today, the Eagle is still a very serious contender to even very modern 4.5 generation aircraft (and while there are 4.5G aircraft like the Eurofighter, Rafale and the newest iterations of the Flanker, the updated Eagle is still a serious and equal match decades after its initial induction. That says a lot about the designers of the F-15, as well as those who ensured it remained relevant and updated).
On the other side of that scale, it is possible to simply pooh-pooh all the designs that are coming out from other nations, and say we possess a 'natural' superiority to anything out there (without realizing that is because of the effort, hardwork, money and dedication put into being number one, and not because of some magical pixie dust that makes it so). Which is why some comments I see from FReepers (e.g. F-16s and A-10s are enough) are quite worrying. The US is number 1 because it has taken cogent steps to be number 1. Stop doing that, and in a couple of decades things may be quite different.
Anyways, it is much better to 'over react' and have a solution like the F-15 (or, more recently, the F-22) facing off against threats that are not near F-15 level; rather underestimating a threat that turns out real.