i've to say SAK is the icon of MacGyver. Unless Mac used it in the show interchangeably with Leatherman. Otherwise, It's impossible to sudden have Mac using one in the show.
Leatherman multi-tools were not as develop and durable back then i believe. But if you look again NOW. It's really another dimension with all the sizes and models you can choose from. Pliers does come in handy in some suitation for some people.
One thing that I don't like about Leatherman tools is that, many of the models don't have plastic handle, which gives no insulation on whatever you're trying to do with your tool. Unfortunately, that's also their trademark.
The newer Lite version of SAKs have LED light. It could be useful in some cases (can't be used as a flashlight)
I always don't get why most of the SAKs have two blades when you only need one. It wastes a slot for another tool. Enlighten me if you know the reason behind this!!
While Leatherman only has one main blade, it frees out a slot for another tool. And its bottle opener and can opener are actually
RDA had his reason carrying a Leatherman when biking. Pliers can adjust basically everything on a bike. Don't think SAKs' miniature pilers can do it effectively, plus the SAK models with pilers usually are very thick. It's one's preference to choose width over thickness i guess. Of course, RDA isn't MacGyver in his normal life
I think it's more interesting to see how someone uses his multi-tools more than what tool he/she's using. I'd like to see a show that uses a Leatherman tool extensively though, really wish to see another MacGyver type of show. Moreover, please bare in mind that, SAK was created by the Swiss. If you're loyal to america, you may want to support Leatherman

I use both SAK and Leatherman, so I'm not bias on any of the side.