To begin with, I'm Taiwanese, but this post does not represent the opinion from Taiwanese pool fans as a whole.
Yang has been considered the best 9-ball player in Taiwan for almost the entire past decade, but now he's faced with a lot more challengers that are either the same age as him or just young and up n' coming like Wu, which shows that he's not as dominate as he ever used to.
I think Yang's weakness lies in the lack of all-around skills; he does not play any game other than 9ball (he competed in 8ball a few years ago and did do well), and he's always thought of as the best shot-making(aggressive) player but a rather mediocare safety and finesse player, both of which are vital for a player as he grows older and gradually loses his shotmaking ability/runout power.
True as some say the best defense is offense since it does not give your opponent even a chance to come back to the table but you can't be in stroke every single time and you have to pass on some tough shots by playing safeties. I have yet to see those improvements in Yang's game.
Another thing is that he doesn't compete abroad nearly as frequently as any player at his level; this is, however, not really his fault. No sponsorship for players in Taiwan, on top of lack of language ability(English), really prevents those pool gems in Taiwan from coming overseas to showcase their games, as well as learn from players in other continents who play with different styles, on a regular basis like Philippinos do.
Don't get me wrong though, Yang is still one of the best in Taiwan, as I mentioned above, and FEARED by his fellow players when it comes to playing for dough. It's just a pity to see such talent get wasted.
Oops maybe I should comment on the possible future matchup between Yang and SVB in order to fit in this topic? I think SVB is a great player but needs to be tested by time because this "SVB hype" only came up about a little more than a year ago; it's a good thing to see that he tries to play all kinds of games and that he does well in tournaments as well as money games, which in my humble opinion is the real definition of a great player. OK I'll be lame and say it's a coin toss!