I have a Leatherman Wave and while I do love it and carry it a lot I don't think its as tough or as well built as the Swiss Tool. I like several things about the Leatherman better though. One and probably tops is the one hand opening blades, but second is the pliers. They are more real needle nose type than the Swiss Tool. I also find the scissors to be quite an advantage on the Wave but if you ask me which is the toughest. I'd rate the Swiss Tool tops in toughess compared to any of them and I've owened or had the chance to handle about every one of the ones available from the cheaper ones you can buy at farm supply stores to Bear Jaws, Schrade, Buck, Gerbers, SOGs, Kershaw (when they still made one) and Spyderco. Vic tops them all. I like the finish on the Vic better too.
STR