I knew I could count on you VT.
Okay, so the most glaring problem with the tools is that the knife is on the wrong side for use and for easy access without opening up the tool. One tool that gets it right is the SwissTool. (Pictured above). NOTE that before sturdy blade locks were used on multi-tools, having the blade edge close on the opposing handle was a _good_ thing.
Now, the supertool (pictured above) is old and will be shortly replaced by some new models this fall. BUT Leathermans that have the blade on the correct side of the tool include:
1. LM Squirt (S4, P4, and radio shack).
2. LM wave (old style)*
3. All Juice series (C2, S2, Kf4, CS4, XE6)
4. New wave*
5. Charge (XTi and Ti)*
* - has locking blade.
So LM has eliminated this "issue" on most of their tools (12 models). Plus most of them are locking (including all where the blade is on the "wrong" side like the pictured supertool.)
The other issue is having a bulky tool behind the blade. Well, that cannot be avoided if you want a tool with pliers. Larger SAKs (my cybertool 41) are just as bulky behind the blade, and the LM Juice (C2,S2 and KF4) are plenty slim behind the blade, yet still include pliers and wirecutters.
Another issue is the blade grind, which can be more obtuse on LMs. That generally is not an issue for me because I thin them before I carry.
Finally, some tough jobs benefit from locking blades, which are more often found on multi-tools (although some SAKs have them).
Of course if you don't need pliers, then a SAK with the tools you do need is more economical and if you need few tools, a SAK is _usually_ more compact (though the LM Juices are very tool-dense)...
Now, the original question was about durability. I think both SAKs and LMs are very tough when it comes to kinetic abuse. I have cracked and melted SAK scales, but they (scales) are cheap and easy to replace.
As I mentioned above, I cannot arrive at a conclusion about corrosion. SAKs report less corrosion problems, but again, LM (as more tool) are usually left in tool-like locations and/or tougher jobs where the elements are harsh and they may not get cleaned as often as a smaller SAK that rides in a pocket. The only way to really know is to saltwater test a clean wave against a clean SAK and see if they rust at different rates and how that corrosion changes their function.
I would depend heartily on either, or both. Just make sure whatever you carry has all the tools you would likely need (and the ones which may be important even if you don't need them - a saw/file comes to mind) And carry it all the time if possible.
