Simple answer. TB will retain tension much longer. All the Luxilon BB strings I've used perform great for about 2 hours then it seems like they never settle on a tension. I guess that's why they are so popular on tour because restringing often is a no issue. TB is a really good string IMHO and also cheaper for the common man.
"The quality and character of people can be seen in the way they treat their animals", Head Speed MP315 16x19, 4.5 - 5.0 level. Power/spin