Oh dear. What was a perfectly reasonable post has turned in to a slanging match.
I too have found TCAS to be reasonably accurate. I too have found that Japanese airspace is busy. If you put these two together the original post is of some concern.
The concern with some of the posts is that they show an amount of complacency which is worrying. If you get a TCAS warning you don't say 'Oh its okay, its inaccurate in azimuth', you react to it!
The comment by ATC Watcher was NOT racist it was a statement of fact. Some people will call any criticism racist! And unFaire D'Income my point about the miles per minute clearly needed to be pointed out as you are so keen to sweep it all away as irelevant!