If saks count then the Wenger giant...
I always found the LM Crunch to be a nice bit of engineering. Its a complex design that isnt repeated by others.
There are a lot of innovations in the new Wave. I'm not sure it's the most sophisticated, but it's pretty incredibly well thought out. There are 7 locking systems on the tool. 4 for the outboard tools, 2 for the inboard tools, and one that prevents the blades from opening while in plier configuration. That's pretty awesome.Then there are two bit holders.Then there's a system to capture add-ons like a belt clip.It might be showing some age, but man... every time I look at it, I kind of marvel at the design.
Perhaps I read "sophisticated" differently but any Learherman I tried is crude by Swiss standards and Gerbers/ SOGs look barbarian compared to Leatherman tools, so the most sophisticated are the Swisstool and Spirit. They pack more tools, have individual springs, precision locks, jewel-like finish, watchmaking tolerances, unparalleled ergonomy, tools with more than a century of evolution behind, artistically valued design and, compared to others, look like Bolsoi ballet dancers vs truck drivers.