rolling said:
T-bin: 80lm/w U-Bin: 100lm/w
Not quite - those are just nominal figures, and the actual bins cover a range of brightnesses - T is 70 to 91 and U is 91 to 118. Given they don't have separate production runs of T and U bin parts, they are simply graded after production, the chances are they are a lot closer than that - from the testing I've seen I'd suggest T bin is actually ~88lm and U bin ~95lm.
In answer to the original question, I'd suggest neither. From what I can see of those stars they both look like the ones which first came out for the XR-E, which have poor thermal performance - in other words the LED will be considerably hotter than it needs to be, resulting in less light and a shorter life. Personally I'd wait until the factory stars come out for the SSC, as these will have much better thermal performance - though I don't think even that linked U bin looks right - though this does:
http://www.leds.de/product_info.php?info=p266_Seoul-Z-Power-LED-P4-star--white--240-lumen.html
Of course these parts are more expensive, but that seems to be the difference between T and U bin parts anyway, given how much more desireable the U bin is. You pays your money and takes your choice.