I think he should be an unstoppable monster who hardly ever loses, and when he does it means something. As it is, he can cut all the mean promos he wants, but to me after all these years of being goofy & shit, beating him means nothing. Beating Andre never stopped meaning something until he was so old that he couldn't walk.
I know its not 1986 anymore, but when Big Show isn't involved in a key angle, he should be winning battle royals and beating three jobbers at once to keep him strong. Throw in a few tag team runs with another monster, and even in the weekly TV era you can find creative ways to do it.
I don't think he's terrible, but I personally have very little interest in anything he does. It's like when Sami Callihan comes on the screen in DGUSA or Takeshi Morishima in NOAH. Meh, i'll sit through this and not care.