Easy call.
Turkish service is fine when everything works smoothly, the flight departs on time, your connection works out, etc.
But if something -- anything -- does not go according to plan, you are screwed on TK. And they are hapless to proactively solve problems. Everything is "my friend, my friend, please understand." That would *never* happen on LX, or in ZRH. Both are efficient, punctual, and professionally run. Those are three adjectives that I think few among us would choose to describe TK.
Take it from someone who just spent 13 unplanned overnight hours in IST thanks to a huge TK delay and subsequent misconnect. With an infant in tow. Not keen to repeat that experience.
If it is a head to head choice, LX will get all of my business going forward.