I find it interesting that you are more idealistic about the Boomers jersey whereas I am more pragmatic. But when it comes to the question of a players level of effort on the international stage, you seem more cynical than I.
I agree with Big Ads in that a professional sportsman's performance, Maric and Irving included, would be 100% regardless of which colours they wear.
Having said this, you often hear comments from American coaches regarding international players, who in regular professional play are seemingly solid players, but not world beaters. However, when donning the national colours, they seem to grow a third arm.
So I guess the question then becomes, does a 100% Kyrie Irving give you more than, say, a Gibson, Markovic or Martin with a third arm? As much as I respect those three players, I would argue that, yes, it does.
However, there are few whose opinions I respect more than yours, paul. Perhaps mine is just a different perspective.