Man do I miss the "thud thud" sound of the D-Throw. I've been making a steady move towards using B-Throw and F-Throw, but Ankoku makes a good point that D-Throw, while its nearly impossible to get the guaranteed combo out of it (unless they're at like 0%), it can make for some great follow up if you bait an air-dodge. D-Throw almost always sends at roughly the same trajectory (45-60 degrees) despite the throw being so DI'able from Sheik like most people do. Also, most people tend to air-dodge immediately expecting an aerial follow-up. This allows Sheik to once again, utilize her insane mind-games game and catch the opponent in an unexpected delayed B-Air, fall straight into an F-Tilt, or get caught in a ghetto-chain grab.
While the F-Throw and B-Throw are unique in their own sense with the DI trap, I feel you can accomplish the same kind of "bait" tactic employed with the D-Throw. But the DI is much less predictable with these throws and it doesn't have that much feared "thud thud" sound that forces everyone to DI the same way that the D-Throw does. I feel the F-Throw and B-Throw make a much better mix-up to confuse the opponent into making bad DI decisions as they are executed more quickly (once again, one "thud" vs. "thud thud").
As for U-Throw, I almost never use it. What kind of good follow ups can you do with it? It always seems to send them so high that the only way you could follow up immediately was with a U-Air, and forcing an air dodge is trickier given the height.
Overall, it looks like Sheik has a lot of variety on her throw where the trajectory varies drastically from throw to throw. I expected nothing less from our favorite ninja. Maybe going F-Throw and B-Throw all the time isn't the best way to go. I'd love to see D-Throw make a dramatic comeback after Gimpy's thread denouncing it as a crappy throw.
Btw, have you guys heard about Sheik's release-grab on MK being an unescapable Chain-grab to the edge? Can't experiment myself, but I'd love to hear some more info about it.