First of all: I am not an endorser of Thomastik, i woulde glad to be, by the way : )
I love these strings, the swing type, i used all, from 011 to 013. These strings are just great.
I discovered that brand some years ago, i was using the D'Addario chromes. I enjoyed the sound ( more bright than Thomastik, for sure ) but they last for too few time. I needed to change the first two strings ( the E and the B ) almost every week. That was due to the fact that they always became dark and dirty ( and loosing the sound ). I always clean the string after played. Probabilly it depends from by chemical system too but since i switched to Thomastik, i can keep the strings for some months. The strings never become dirty and dark and they last for long, always in tune : ). Actually i really like a new pack of Thomastik strings after a week. In that moment they are perfect: a little more bright sound ( not so much ) and really low tension with silky sound, for the chord and for single line. Before I have had many problem to my fingers ( some kind of pain ) using D'Addario, due to the more big tension and also due to the dirty problem of the first two strings.
Now i am an happy Thomastik guitar player, just sometime i think to try the Be Bop type instead of the Swing. Anyway, i have no more problems to my finger and a great sound : )
Just my humble opinion.
All the Best