considering he is a gm, not a wrestler, and therefore his entire job is acting, he is terrible.
The key lies in that statement; he
is a GM, not a wrestler. As I see it, Raw features more individual conflicts than the other brand. When Cena, Punk and Del Rio are involved in their program, they're not interested in anyone else. They have no interest in Miz, Kofi, or Ryder.
Smackdown is more of a "group" show. Of course, they have individual conflicts too, but the allegiances and feuds are spread among many performers. Christian looks to form alliances with other wrestlers in an effort to further his own ambitions. Zach Ryder aligns himself with
anyone (including the GM) who will help him get some ring time. This lends an air of unpredictability; you never know who's going after who.
With all this, you need a General Manager who can keep order, asserting himself even when facing down wrestlers who could pound him into the ground......and a boss (either Triple H or Vince McMahon) who openly countermand his decisions and show him repeatedly that he doesn't have the absolute authority that the head of Raw does. Contrast it to Triple H, who's actually a wrestler, not a GM. When someone like Punk steps out of line, Triple H gets in the ring and beats him up; a privilege and ability Teddy Long doesn't have.
Given the difficulty of the role, I think Teddy is just fine at what he does. If he's aligning matters in a way the heels don't like, then he's doing a proper job given the limited scope of his authority.
In addition to all this, Teddy does it with flair. No, I'm not talking about Ric Flair, but Teddy sure does his share of stylin' and profilin'.
Teddy's doing just fine.