Just because of the Wide-Body aircraft for the TLV-EU segment I would go with LX. I personally prefer OS over LX for the long haul though.
That was my thought when I booked LX, but I was really disappointed with the product. Lie flat bed is too short and too narrow (laying on my side, FA bumped into my knees with cart).
WiFi is available on LX, though one has to purchase a package, unlike TK which is free for business class.
This thread reminded me that I actually did also fly SN in Fake business ex-TLV. Had to travel urgently and only thing I found was SN TLV-BRU-GVA connecting to UA for GVA-EWR. Nothing good to say about that one, neither SN nor BRU airport is something to look forward to.